70 research outputs found

    Diagnostic challenge in a patient with primary bilateral Dumbbell-shaped lumbar non-Hodgkin’s lymphoma

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    Objective: Primary bilateral dumbbell-shaped lumbar non-Hodgkin lymphomas with epidural and extraspinal involvement, are rare occurrences. Patients presenting at advanced stages and rapid evolution towards neurological impairment lead to diagnostic dilemmas for which only immunohistochemistry can provide a correct, although delayed solution. Case report: We report the first case of a bilateral, dumbbell-shaped, lumbar lymphoma in a 65-year-old man with a medical history of chronic viral hepatitis type B and D under interferon treatment. The patient presented with back pain radiating down the right leg, with rapid progression to paraplegia and sphincter dysfunction. CT and MRI revealed a large dumbbell mass (approx. 5/5/10 cm) in the right paraspinal musculature, at the L4-L5 level, with intraspinal epidural extension. A similar mass of smaller size was described on the left side, almost mirroring the first lesion, the imagistic aspect suggesting a neural sheath tumor. Intraoperatively, in the right lumbar paraspinal musculature, a soft, yellowish region was discovered, the macroscopic appearance being rather suggestive for a diffuse infection. Clinical, imagistic and surgical findings were not conclusive, nor was the histological examination in light microscopy of the surgical specimen or of the bone marrow biopsy. Immunohistochemistry identified the presence of large B cells, leading to the diagnosis of B cell lymphoma. Although the patient was treated with systemic chemotherapy, his condition rapidly deteriorated and he died within 3 months. Conclusions: In the case of a lumbosacral, dumbbell shaped mass, developed both epidural and extraspinal, the differential diagnosis must include lymphoma. The histological examination, especially immunohistochemistry provided the final diagnosis. Delays in establishing a diagnosis, associated with a malignant evolution of lymphoma, diminish the chances of determining and applying a treatment strategy that could prolong survival

    Multiple Smaller Missions as a Direct Pathway to Mars Sample Return

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    Recent discoveries by the Mars Exploration Rovers, Mars Express, Mars Odyssey, and Mars Reconnaissance Orbiter spacecraft include multiple, tantalizing astrobiological targets representing both past and present environments on Mars. The most desirable path to Mars Sample Return (MSR) would be to collect and return samples from that site which provides the clearest examples of the variety of rock types considered a high priority for sample return (pristine igneous, sedimentary, and hydrothermal). Here we propose an MSR architecture in which the next steps (potentially launched in 2018) would entail a series of smaller missions, including caching, to multiple landing sites to verify the presence of high priority sample return targets through in situ analyses. This alternative architecture to one flagship-class sample caching mission to a single site would preserve a direct path to MSR as stipulated by the Planetary Decadal Survey, while permitting investigation of diverse deposit types and providing comparison of the site of returned samples to other aqueous environments on early Mar

    Distribution of hydrated minerals in the north polar region of Mars

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    The previous discovery of extensive deposits of hydrated minerals in Olympia Planum in the north polar region of Mars by the Mars Express OMEGA instrument raises important questions about the origin and subsequent redistribution of these hydrated minerals. Here we present a new map of the distribution of hydrated minerals within the north polar region of Mars by applying both standard and new spectral analysis techniques to near-infrared spectral data from OMEGA. Our results are in agreement with the previous OMEGA observations but also show more extensive detections of hydrated minerals throughout the circumpolar plains, as well as new detections of hydrated minerals on the surface of Planum Boreum and within the polar troughs. We find that while the circumpolar plains hydration signatures appear to be correlated with the dark dunes of the north polar erg, hydration signatures in Planum Boreum instead appear to be correlated with the north polar veneers and their sources within the polar layered deposits. By applying laboratory-derived empirical models of the dependence of gypsum spectra on grain size and abundance, we provide approximate abundance estimates for the hydrated minerals we have identified in Observatoire pour la Minéralogie, l’Eau, les Glaces et l’Activité (OMEGA) and Compact Reconnaissance Imaging Spectrometer (CRISM) data. We find that the presence of hydrated minerals throughout the north polar region suggests (1) a complex cycle of sediment exchange between the Olympia Planum dunes and the other polar units; (2) an earlier origin for the hydrated minerals than originally postulated; and (3) the occurrence of significant water activity in this region during the Amazonian.This work was supported by grants from the Mars Data Analysis Program under contracts from NASA, the Mars Odyssey Participating Scientist program under contracts from the Jet Propulsion Laboratory, and the Canadian Space Agency.https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2008JE00318

    Plasma-wall interaction studies within the EUROfusion consortium: Progress on plasma-facing components development and qualification

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    This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.The provision of a particle and power exhaust solution which is compatible with first-wall components and edge-plasma conditions is a key area of present-day fusion research and mandatory for a successful operation of ITER and DEMO. The work package plasma-facing components (WP PFC) within the European fusion programme complements with laboratory experiments, i.e. in linear plasma devices, electron and ion beam loading facilities, the studies performed in toroidally confined magnetic devices, such as JET, ASDEX Upgrade, WEST etc. The connection of both groups is done via common physics and engineering studies, including the qualification and specification of plasma-facing components, and by modelling codes that simulate edge-plasma conditions and the plasma-material interaction as well as the study of fundamental processes. WP PFC addresses these critical points in order to ensure reliable and efficient use of conventional, solid PFCs in ITER (Be and W) and DEMO (W and steel) with respect to heat-load capabilities (transient and steady-state heat and particle loads), lifetime estimates (erosion, material mixing and surface morphology), and safety aspects (fuel retention, fuel removal, material migration and dust formation) particularly for quasi-steady-state conditions. Alternative scenarios and concepts (liquid Sn or Li as PFCs) for DEMO are developed and tested in the event that the conventional solution turns out to not be functional. Here, we present an overview of the activities with an emphasis on a few key results: (i) the observed synergistic effects in particle and heat loading of ITER-grade W with the available set of exposition devices on material properties such as roughness, ductility and microstructure; (ii) the progress in understanding of fuel retention, diffusion and outgassing in different W-based materials, including the impact of damage and impurities like N; and (iii), the preferential sputtering of Fe in EUROFER steel providing an in situ W surface and a potential first-wall solution for DEMO.European Commission; Consortium for Ocean Leadership 633053; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

    X-ray Diffraction Results from Mars Science Laboratory: Mineralogy of Rocknest at Gale Crater

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    The Mars Science Laboratory rover Curiosity scooped samples of soil from the Rocknest aeolian bedform in Gale crater. Analysis of the soil with the Chemistry and Mineralogy (CheMin) x-ray diffraction (XRD) instrument revealed plagioclase (~An57), forsteritic olivine (~Fo62), augite, and pigeonite, with minor K-feldspar, magnetite, quartz, anhydrite, hematite, and ilmenite. The minor phases are present at, or near, detection limits. The soil also contains 27 ± 14 weight percent x-ray amorphous material, likely containing multiple Fe^(3+)- and volatile-bearing phases, including possibly a substance resembling hisingerite. The crystalline component is similar to the normative mineralogy of certain basaltic rocks from Gusev crater on Mars and of martian basaltic meteorites. The amorphous component is similar to that found on Earth in places such as soils on the Mauna Kea volcano, Hawaii
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