275 research outputs found

    Continuum models of focused electron beam induced processing

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    © 2015 Toth et al. Focused electron beam induced processing (FEBIP) is a suite of direct-write, high resolution techniques that enable fabrication and editing of nanostructured materials inside scanning electron microscopes and other focused electron beam (FEB) systems. Here we detail continuum techniques that are used to model FEBIP, and release software that can be used to simulate a wide range of processes reported in the FEBIP literature. These include: (i) etching and deposition performed using precursors that interact with a surface through physisorption and activated chemisorption, (ii) gas mixtures used to perform simultaneous focused electron beam induced etching and deposition (FEBIE and FEBID), and (iii) etch processes that proceed through multiple reaction pathways and generate a number of reaction products at the substrate surface. We also review and release software for Monte Carlo modeling of the precursor gas flux which is needed as an input parameter for continuum FEBIP models

    Ki-67 expression in soft tissue sarcomas in children

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    Metatarsophalangeal joint pain in psoriatic arthritis: a cross-sectional study

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    Methods. Thirty-four consecutive patients with PsA (mean age 45.3 years, 65% female, mean disease duration 9.9 years) and 22 control participants (mean age 37.9 years, 64% female) underwent clinical and US examination to determine the presence of pain, swelling, synovitis, erosions, effusions and submetatarsal bursae at the MTP joints. Mean barefoot peak plantar pressures were determined at each MTP joint. Levels of pain, US-determined pathology and peak pressures were compared between groups. Binary logistic regression was used to identify demographic, clinical examination-derived, US-derived and plantar pressure predictors of pain at the MTP joints in the PsA group. Results. The presence of pain, deformity, synovitis, erosions (P < 0.001) and submetatarsal bursae and peak plantar pressure at MTP 3 (P < 0.05) were significantly higher in the PsA group. MTP joint pain in PsA was independently predicted by high BMI, female gender and the presence of joint subluxation, synovitis and erosion. Conclusion. These results suggest local inflammatory and structural factors, together with systemic factors (gender, BMI), are predominantly responsible for painful MTP joints in PsA, with no clear role for plantar pressure characteristics

    SUPERFLUID CHARACTERISTICS OF INDUCED-PAIRING MODEL

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    We study the electromagnetic and thermodynamic properties of a model of coexisting local electron pairs and itinerant carriers coupled via the intersubsystem charge exchange. The calculations of the London penetration depth, the energy gap, the magnetic critical fields and the coherence length in the superconducting phase are performed. The effects of reduced binding energy of local pairs are discussed. The 'considered effective Hamiltonian of coexisting localized d-electrons and itinerant c-electrons can be written as where E0 measures the relative position of d-level with respect to the bottom of the c-electron band εk in the absence of interactions, is the chemical potential which ensures that a total number of particles is constant, i.e. n = n, -I-n a = (Σkσ (ck ckσ) + Σi σ (n ó)) /N, U is the effective on-site density interaction between d-electrons, t is the hopping integral for c-electrons and I0 is the intersubsystem charge exchange coupling. The Peierls factor in Eq. (1) account for the coupling of electrons to the magnetic field via its vector potential A(r). Φij = -fi g f' drA(r), and e is the electron charge. In analysis we used the variational approach which treats the on-site interaction term U exactl

    The EULAR-OMERACT rheumatoid arthritis MRI reference image atlas: the wrist joint

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    This paper presents the wrist joint MR images of the EULAR–OMERACT rheumatoid arthritis MRI reference image atlas. Reference images for scoring synovitis, bone oedema, and bone erosions according to the OMERACT RA MRI scoring (RAMRIS) system are provided. All grades (0–3) of synovitis are illustrated in each of the three wrist joint areas defined in the scoring system—that is, the distal radioulnar joint, the radiocarpal joint, and the intercarpal-carpometacarpal joints. For reasons of feasibility, examples of bone abnormalities are limited to five selected bones: the radius, scaphoid, lunate, capitate, and a metacarpal base. In these bones, grades 0–3 of bone oedema are illustrated, and for bone erosion, grades 0–3 and examples of higher grades are presented. The presented reference images can be used to guide scoring of wrist joints according to the OMERACT RA MRI scoring system

    Are bone erosions detected by magnetic resonance imaging and ultrasonography true erosions? A comparison with computed tomography in rheumatoid arthritis metacarpophalangeal joints

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    The objective of the study was, with multidetector computed tomography (CT) as the reference method, to determine whether bone erosions in rheumatoid arthritis (RA) metacarpophalangeal (MCP) joints detected with magnetic resonance imaging (MRI) and ultrasonography (US), but not with radiography, represent true erosive changes. We included 17 RA patients with at least one, previously detected, radiographically invisible MCP joint MRI erosion, and four healthy control individuals. They all underwent CT, MRI, US and radiography of the 2nd to 5th MCP joints of one hand on the same day. Each imaging modality was evaluated for the presence of bone erosions in each MCP joint quadrant. In total, 336 quadrants were examined. The sensitivity, specificity and accuracy, respectively, for detecting bone erosions (with CT as the reference method) were 19%, 100% and 81% for radiography; 68%, 96% and 89% for MRI; and 42%, 91% and 80% for US. When the 16 quadrants with radiographic erosions were excluded from the analysis, similar values for MRI (65%, 96% and 90%) and US (30%, 92% and 80%) were obtained. CT and MRI detected at least one erosion in all patients but none in control individuals. US detected at least one erosion in 15 patients, however, erosion-like changes were seen on US in all control individuals. Nine patients had no erosions on radiography. In conclusion, with CT as the reference method, MRI and US exhibited high specificities (96% and 91%, respectively) in detecting bone erosions in RA MCP joints, even in the radiographically non-erosive joints (96% and 92%). The moderate sensitivities indicate that even more erosions than are seen on MRI and, particularly, US are present. Radiography exhibited high specificity (100%) but low sensitivity (19%). The present study strongly indicates that bone erosions, detected with MRI and US in RA patients, represent a loss of calcified tissue with cortical destruction, and therefore can be considered true bone erosions
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