71 research outputs found

    Metastatic potential of an aneurysmal bone cyst

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    Aneurysmal bone cysts (ABCs) are benign bone tumors consisting of blood-filled cavities lined by connective tissue septa. Recently, the hypothesis that ABCs are lesions reactive to local hemodynamics has been challenged after the discovery of specific recurrent chromosomal abnormalities. Multiple cases of malignant transformation of ABC into (osteo)sarcoma have been described, as well as a number of cases of telangiectatic osteosarcoma which had been misdiagnosed as ABC. We herewith document a case of a pelvic ABC metastatic to the lung, liver, and kidneys. Diagnosis was confirmed by the presence of a break in the USP6 gene, which is pathognomonic for ABC, in a pulmonary metastasis of our patient. Sarcomatous transformation as an explanation for this behavior was ruled out by demonstrating diploid DNA content in both the pulmonary lesion and the primary tumor

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≄20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≀pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≀{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Compound effect of EHD and surface roughness in pool boiling and CHF with R-123

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    This article is a post-print version of the fianl published article which may be accessed at the link below.Saturated pool boiling of R-123 at 1 bar, including the critical heat flux (CHF), was enhanced by modifying the surface characteristics and applying a high intensity electrostatic field, the latter termed electrohydrodynamic (and abbreviated EHD) enhancement. The heat flux was varied from very low values in the natural convection regime up to CHF. Experiments were performed with increasing and decreasing heat flux to study boiling hysteresis without and with EHD. Boiling occurred on the sand blasted surface of a cylindrical copper block with embedded electrical heating elements, with standardized surface parameter Pa = 3.5 ÎŒm. The electric field was generated by a potential of 5 kV to 25 kV, applied through a 40 mm diameter circular electrode of ss-304 wire mesh, aperture size 5.1 mm, located at distances of 5 - 60 mm from the surface, with most of the data obtained for 20 mm. The data for the rough surface were compared with earlier data for a smooth surface and indicated a significant increase in the heat transfer rates. EHD produced a further increase in the heat transfer rates, particularly at low heat flux values and near the CHF. Boiling hysteresis was reduced progressively by EHD and eliminated at high field strength.This work was supported by Government of Pakistan under a scholarship programme

    A Multicriteria Economic Analysis Model for Urban Forestry Projects

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    The urban green areas represent a strategic resource for the contemporary city sustainable development. In addition to aesthetic and recreational functions, their presence contributes to increase the environmental quality level by improving the microclimate, preserving the biodiversity and promoting the territory economic growth. However, the interventions execution designed to provide the built areas of the so-called urban forests is rarely indicated as a priority action in the urban spaces planning because often a different allocation of available resources is preferred. In this work, starting from the definition of a indicators set useful for expressing the not only financial, but also social, cultural and environmental components of value of the projects for urban forestry, the aim is to build a multi-criteria economic analysis protocol purposeful at predicting the correct funds distribution between initiatives for realization of urban forests at a district scale. The characterization of the model is carried out through the logical-mathematical tools of the Operational Research developed according to Continuous Linear Programming principles

    Efficient antigen presentation of soluble, but not particulate, antigen in the absence of Wiskott–Aldrich syndrome protein

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    B cells and dendritic cells, lacking functional Wiskott–Aldrich syndrome protein (WASP), have aberrant formation of membrane protrusions. We hypothesized that protrusions may play a role in antigen presentation, and consequently, that impaired antigen presentation may be an underlying factor of the immune deficiency in patients with Wiskott–Aldrich syndrome. In this paper, we investigated the antigen presentation capacity of B cells and dendritic cells from WASP knockout mice, using soluble and particulate antigen, to CD4(+) T cells from T-cell receptor transgenic DO11.10 mice. As antigen we used soluble ovalbumin (OVA), a peptide thereof (amino acids 323–339) or bacteria expressing OVA. We found that WASP-deficient B cells and dendritic cells efficiently processed and presented soluble OVA protein as well as its peptide in vitro, inducing proliferation and cytokine production from CD4(+) T cells. Antigen presentation of soluble protein was efficient also in vivo, because immunization of WASP-deficient mice with OVA elicited proliferation of transferred, fluorescent-labelled, CD4(+) T cells. Although we could detect uptake of bacteria in dendritic cells, processing and presentation of bacterial-expressed OVA was impaired in WASP-deficient dendritic cells. In conclusion, our data suggest that WASP is not needed for processing and presentation of soluble antigen, but that efficient presentation of particulate antigen require WASP
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