82 research outputs found

    Calibration activities on the BepiColombo High-Resolution Channel (HRIC) of SIMBIO-SYS instrument

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    HRIC (High Resolution Imaging Channel) is the high resolution channel of the SIMBIO-SYS instrument on- board the ESA BepiColombo Mission. Calibration activities were performed at SelexES premises in spring- summer 2014 in order to check for Channel performances (radiometric performances, quality image and geometrical performances) and to obtain data necessary to setup a calibration pipeline necessary to process the raw images acquired by the channel when in operative scenario

    Genomic and clinical findings in myeloid neoplasms with PDGFRB rearrangement

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    Platelet-derived growth factor receptor B (PDGFRB) gene rearrangements define a unique subgroup of myeloid and lymphoid neoplasms frequently associated with eosinophilia and characterized by high sensitivity to tyrosine kinase inhibition. To date, various PDGFRB/5q32 rearrangements, involving at least 40 fusion partners, have been reported. However, information on genomic and clinical features accompanying rearrangements of PDGFRB is still scarce. Here, we characterized a series of 14 cases with a myeloid neoplasm using cytogenetic, single nucleotide polymorphism array, and next-generation sequencing. We identified nine PDGFRB translocation partners, including the KAZN gene at 1p36.21 as a novel partner in a previously undescribed t(1;5)(p36;q33) chromosome change. In all cases, the PDGFRB recombination was the sole cytogenetic abnormality underlying the phenotype. Acquired somatic variants were mainly found in clinically aggressive diseases and involved epigenetic genes (TET2, DNMT3A, ASXL1), transcription factors (RUNX1 and CEBPA), and signaling modulators (HRAS). By using both cytogenetic and nested PCR monitoring to evaluate response to imatinib, we found that, in non-AML cases, a low dosage (100–200 mg) is sufficient to induce and maintain longstanding hematological, cytogenetic, and molecular remissions

    The measurement of the noise-equivalent spectral radiance of SIMBIO-SYS/VIHI spectrometer

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    We report about the measurement of the Noise- Equivalent Spectral Radiance (NESR) of the VIHI imaging spectromter aboard ESA's Bepi Colombo mission to Mercury. The knowledge of the NESR allows to determine the capability of an optical detector to measure faint signals. A description of the setup used to determine the NESR during the prelaunch calibration campaign is given. The processing of the data col- lected at various operative temperatures and integration times is described. The sensitivity study of the NESR has been performed at the expected detector's temperatures and integration times with the goal to determine the minimum spectral radiance at which VIHI is sensitive during the different observation phases of the mission. A simulation of the expected Signal-to-Noise Ratio (SNR) of VIHI during the different orbital phases is provided

    Radiometric calibration of the SIMBIO-SYS STereo imaging Channel

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    The STereo imaging Channel (STC) is a double wide-angle camera developed to be one of the channels of the SIMBIOSYS instrument onboard of the ESA BepiColombo mission to Mercury. STC main goal is to map in 3D the whole Mercury surface. The geometric and radiometric responses of the STC Proto Flight model have been characterized on-ground during the calibration campaign. The derived responses will be used to calibrate the STC images that will be acquired in flight. The aim is to determine the functions linking the detected signal in digital number to the radiance of the target surface in physical units. The result of the radiometric calibration consists in the determination of well-defined quantities: (1) the dark current as a function of the integration time and of the detector temperature, settled and controlled to be stable at 268 K; (2) the read out noise, which is associated with the noise signal of the read-out electronic; and (3) the fixed pattern noise, which is generated by the different response of each pixel. Once these quantities are known, the photon response and the photoresponse non-uniformity, which represents the variation of the photon responsivity of a pixel in an array, can be derived. The final result of the radiometric calibration is the relation between the radiance of an accurately known and uniform source, and the digital numbers measured by the detector

    clinico pathological features treatments and survival of malignant insulinomas a multicenter study

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    Introduction Management of malignant insulinomas is challenging due to the need to control both hypoglycaemic syndrome and tumor growth. Literature data is limited to small series. Aim of the study To analyze clinico-pathological characteristics, treatments and prognosis of patients with malignant insulinoma. Materials and methods Multicenter retrospective study on 31 patients (male: 61.3%) diagnosed between 1988 and 2017. Results The mean age at diagnosis was 48 years. The mean NET diameter was 41 ± 31 mm, and 70.8% of NETs were G2. Metastases were widespread in 38.7%, hepatic in 41.9% and only lymph nodal in 19.4%. In 16.1% of the cases, the hypoglycaemic syndrome occurred after 46 ± 35 months from the diagnosis of originally non-functioning NET, whereas in 83.9% of the cases it led to the diagnosis of NET, of which 42.3% with a mean diagnostic delay of 32.7 ± 39.8 months. Surgical treatment was performed in 67.7% of the cases. The 5-year survival rate was 62%. Overall survival was significantly higher in patients with Ki-67 ≤10% (P = 0.03), insulin level <60 µU/mL (P = 0.015) and in patients who underwent surgery (P = 0.006). Peptide Receptor Radionuclide Therapy (PRRT) was performed in 45.1%, with syndrome control in 93% of patients. Conclusions Our study includes the largest series of patients with malignant insulinoma reported to date. The hypoglycaemic syndrome may occur after years in initially non-functioning NETs or be misunderstood with delayed diagnosis of NETs. Surgical treatment and Ki67 ≤10% are prognostic factors associated with better survival. PPRT proved to be effective in the control of hypoglycaemia in majority of cases

    SIMBIO-SYS : Scientific Cameras and Spectrometer for the BepiColombo Mission

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    The SIMBIO-SYS (Spectrometer and Imaging for MPO BepiColombo Integrated Observatory SYStem) is a complex instrument suite part of the scientific payload of the Mercury Planetary Orbiter for the BepiColombo mission, the last of the cornerstone missions of the European Space Agency (ESA) Horizon + science program. The SIMBIO-SYS instrument will provide all the science imaging capability of the BepiColombo MPO spacecraft. It consists of three channels: the STereo imaging Channel (STC), with a broad spectral band in the 400-950 nm range and medium spatial resolution (at best 58 m/px), that will provide Digital Terrain Model of the entire surface of the planet with an accuracy better than 80 m; the High Resolution Imaging Channel (HRIC), with broad spectral bands in the 400-900 nm range and high spatial resolution (at best 6 m/px), that will provide high-resolution images of about 20% of the surface, and the Visible and near-Infrared Hyperspectral Imaging channel (VIHI), with high spectral resolution (6 nm at finest) in the 400-2000 nm range and spatial resolution reaching 120 m/px, it will provide global coverage at 480 m/px with the spectral information, assuming the first orbit around Mercury with periherm at 480 km from the surface. SIMBIO-SYS will provide high-resolution images, the Digital Terrain Model of the entire surface, and the surface composition using a wide spectral range, as for instance detecting sulphides or material derived by sulphur and carbon oxidation, at resolutions and coverage higher than the MESSENGER mission with a full co-alignment of the three channels. All the data that will be acquired will allow to cover a wide range of scientific objectives, from the surface processes and cartography up to the internal structure, contributing to the libration experiment, and the surface-exosphere interaction. The global 3D and spectral mapping will allow to study the morphology and the composition of any surface feature. In this work, we describe the on-ground calibrations and the results obtained, providing an important overview of the instrument performances. The calibrations have been performed at channel and at system levels, utilizing specific setup in most of the cases realized for SIMBIO-SYS. In the case of the stereo camera (STC), it has been necessary to have a validation of the new stereo concept adopted, based on the push-frame. This work describes also the results of the Near-Earth Commissioning Phase performed few weeks after the Launch (20 October 2018). According to the calibration results and the first commissioning the three channels are working very well.Peer reviewe

    A new real time Doppler centroid estimator for airborne SAR systems

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    We present a new algorithm to estimate the Doppler centroid (DC) of a SAR signal, and discuss its real-time implementation. The algorithm is called the Zero-crossing Doppler Estimator (ZDE), since it exploits the fact that the number of zero-crossings of the in-phase and quadrature channels is minimum when the azimuth received signal is processed by using the correct DC. We prove that the ZDE algorithm is appropriate for real-time applications, since it is computationally very efficient, needs very little storage memory, and is fully automatic; a first guess of DC is not needed. Nevertheless, the results obtained with simulated data prove that the computational efficiency is not achieved at the expense of the estimate accuracy, which is in fact comparable to the one of the existing techniques
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