1,444 research outputs found

    High frequency of inadequate test requests for antiphospholipid antibodies in daily clinical practice

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    Abstract Background: We have empirically noted that many physicians routinely request anti-phospholipid antibodies (aPL) without a correct clinical indication. The aim of this study was to evaluate retrospectively whether aPL testing at our Thrombosis Centre was justified. Methods: Medical records from 520 subjects for aPL screening tests for various clinical conditions were reviewed. The aPL screening tests were: lupus anticoagulant (LA), anti-cardiolipin antibodies (aCL) and anti-β(2) glycoptotein I (aβ(2) GPI). Requests for aPL screening were divided into justified, potentially justified or not adequately justified. Results: aPL testing requests were considered justified in 358 (69%) patients, potentially justified in 66 (12.6%) and not adequately justified in 96 (18.4%). LA was positive in 65 (18%) of justified requests and in only one (1%) of the 96 potentially justified requests. None of the 66 not adequately justified for aPL testing was positive for LA. aβ(2) ..

    Neural regulation of cardiovascular response to exercise: role of central command and peripheral afferents

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    During dynamic exercise, mechanisms controlling the cardiovascular apparatus operate to provide adequate oxygen to fulfill metabolic demand of exercising muscles and to guarantee metabolic end-products washout. Moreover, arterial blood pressure is regulated to maintain adequate perfusion of the vital organs without excessive pressure variations. The autonomic nervous system adjustments are characterized by a parasympathetic withdrawal and a sympathetic activation. In this review, we briefly summarize neural reflexes operating during dynamic exercise. The main focus of the present review will be on the central command, the arterial baroreflex and chemoreflex, and the exercise pressure reflex. The regulation and integration of these reflexes operating during dynamic exercise and their possible role in the pathophysiology of some cardiovascular diseases are also discusse

    Constraints on the environment and energetics of the Broad-Line Ic SN2014ad from deep radio and X-ray observations

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    Broad-line type Ic Supernovae (BL-Ic SNe) are characterized by high ejecta velocity (104\gtrsim 10^4 km s1^{-1}) and are sometimes associated with the relativistic jets typical of long duration (2\gtrsim 2 s) Gamma-Ray Bursts (L-GRBs). The reason why a small fraction of BL-Ic SNe harbor relativistic jets is not known. Here we present deep X-ray and radio observations of the BL-Ic SN2014ad extending from 1313 to 930930 days post explosion. SN2014ad was not detected at either frequency and has no observational evidence of a GRB counterpart. The proximity of SN2014ad (d26d\sim 26 Mpc) enables very deep constraints on the progenitor mass-loss rate M˙\dot{M} and on the total energy of the fast ejecta EE. We consider two synchrotron emission scenarios for a wind-like circumstellar medium (CSM): (i) uncollimated non-relativistic ejecta, and (ii) off-axis relativistic jet. Within the first scenario our observations are consistent with GRB-less BL-Ic SNe characterized by a modest energy budget of their fast ejecta (E1045E \lesssim 10^{45} erg), like SNe 2002ap and 2010ay. For jetted explosions, we cannot rule out a GRB with E1051E \lesssim 10^{51} erg (beam-corrected) with a narrow opening angle (θj5\theta_j \sim 5^{\circ}) observed moderately off-axis (θobs30\theta_{\rm obs} \gtrsim 30^{\circ}) and expanding in a very low CSM density (M˙\dot{M} 106\lesssim 10^{-6} M_{\odot} yr1^{-1}). Our study shows that off-axis low-energy jets expanding in a low-density medium cannot be ruled out even in the most nearby BL-Ic SNe with extensive deep observations, and might be a common feature of BL-Ic SNe.Comment: 9 pages, 5 figures, accepted in Ap

    Taming Data Caches for Predictable Execution on GPU-based SoCs

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    Heterogeneous SoCs (HeSoCs) typically share a single DRAM between the CPU and GPU, making workloads susceptible to memory interference, and predictable execution troublesome. State-of-the art predictable execution models (PREM) for HeSoCs prefetch data to the GPU scratchpad memory (SPM), for computations to be insensitive to CPU-generated DRAM traffic. However, the amount of work that the small SPM sizes allow is typically insufficient to absorb CPU/GPU synchronization costs. On-chip caches are larger, and would solve this issue, but have been argued too unpredictable due to self-evictions. We show how self-eviction can be minimized in GPU caches via clever managing of prefetches, thus lowering the performance cost, while retaining timing predictability

    The biology and treatment of acute long-bones diaphyseal fractures: Overview of the current options for bone healing enhancement

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    Diaphyseal fractures represent a complex biological entity that could often end into impaired bone-healing, with delayed union and non-union occurring up to 10% of cases. The role of the modern orthopaedic surgeon is to optimize the fracture healing environment, recognize and eliminate possible interfering factors, and choose the best suited surgical fixation technique. The impaired reparative process after surgical intervention can be modulated with different surgical techniques, such as dynamization or exchange nailing after failed intramedullary nailing. Moreover, the mechanical stability of a nail can be improved through augmentation plating, bone grafting or external fixation techniques with satisfactory results. According to the “diamond concept”, local therapies, such as osteoconductive scaffolds, bone growth factors, and osteogenic cells can be successfully applied in “polytherapy” for the enhancement of delayed union and non-union of long bones diaphyseal fractures. Moreover, systemic anti-osteoporosis anabolic drugs, such as teriparatide, have been proposed as off-label treatment for bone healing enhancement both in fresh complex shaft fractures and impaired unions, especially for fragility fractures. The article aims to review the biological and mechanical principles of failed reparative osteogenesis of diaphyseal fractures after surgical treatment. Moreover, the evidence about the modern non-surgical and pharmacological options for bone healing enhancement will discussed

    Numerical simul tion of droplet impact erosion : dang van fatigue approach

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    The aim of this work is to understand the erosion mechanism caused by repeated water droplets impingement on a metallic structure, and then perform numerical simulations of the damage. When a high velocity water droplet with small diameter impacts a rigid surface, interaction is driven by inertial effects. Upon impact, the “water-hammer” pressure appears by inertial effect at the center of the contact though the maximum pressure occurs on the envelope of the contact area. Lateral jetting occurs by compression when the wave front travelling inside droplet overtakes the contact area. Concerning the structure, erosion is due to fatigue crack- ing. First, material grains are weakened during an “incubation” phase. After a large number of impacts, micro-cracks emerge and lead to ejection or fracture of grains, what is called “am- plification” phase. Numerical simulation including rigid solid allows to locate the most loaded zones of the area, by observing the pressure and mainly the impulse. A 2-way coupling compu- tation with fluid-structure interaction at macroscopic scale allows to confirm the fatigue-based mechanism by observing the hydrostatic stress. Finally, erosion program developed with Dang Van criterion provides the location of the most eroded zones of the structure during a loading cycle. They locate at the edge of jetting zone, which shows the influence of microjets in the erosion mechanism

    Thermal simulations for optical transition radiation screen for Eli-NP compton gamma source

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    The ELI-NP GBS (Extreme Light Infrastructure-Nuclear Physics Gamma Beam Source) is a high brightness elec-tron LINAC that is being built in Romania. The goal for this facility is to provide high luminosity gamma beam through Compton Backscattering. A train of 32 bunches at 100Hz with a nominal charge of 250pC is accelerated up to 740 MeV. Two interaction points with an IR Laser beam produces the gamma beam at different energies. In order to measure the electron beam spot size and the beam proper-ties along the train, the OTR screens must sustain the ther-mal and mechanical stress due to the energy deposited by the bunches. This paper is an ANSYS study of the issues due to the high quantity of energy transferred to the OTR screen. They will be shown different analysis, steady-state and thermal transient analysis, where the input loads will be the internal heat generation equivalent to the average power, deposited by the ELI-GBS beam in 512 ns, that is the train duration. Each analyses will be followed by the structural analysis to investigate the performance of the OTR materi

    Bringing the Embedded Systems Industry Towards Open Source: the SHARE project experience

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    International audienceOpen source software adoption in the embedded systems domain is gaining growing interest within the european industrial and academic communities due to the significant benefits it brings in terms of flexibility and cost reduction.Nonetheless, scepticism about open source as a viable option to support critical business functions still holds, since its decentralized and distributed development model makes quality evaluation and assessment hard to achieve. This paper reports the SHARE project experience, aimed at facilitating and promoting the use of open source software in the embedded systems industry. Performed activities, proposed methodology and achieved results are presented, along with lessons learned to exploit for enabling further initiatives in the next future

    Complications and Intraoperative Fractures in Reverse Shoulder Arthroplasty: A Systematic Review

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    Introduction: The reverse shoulder arthroplasty is nowadays a treatment option for a variety of shoulder problems. As its incidence rose, also the number of complications increased, including intraoperative fractures. Significance: We performed a systematic review and critical analysis of the current literature following the PRISMA guidelines. Our purpose was to: 1) determine incidence, causes, and characteristics of intraoperative fractures; 2) evaluate their current treatment options, possible related complications, reoperation rates, and the patients’ outcome; and 3) determine the overall incidence of each complication related to reverse shoulder arthroplasty. The articles were selected from PubMed medical database in April 2020 using a comprehensive search strategy. Rayyan software was used to support the selection process of the records. A descriptive and critical analysis of the results was performed. Results: The study group included a total of 13,513 reverse shoulder arthroplasty procedures. The total number of complications was 1647 (rate 12.1%). The most common complication was dislocation (340 cases, rate 2.5%). Forty-six studies reported a total of 188 intraoperative fractures among the complications (rate 1.4%). The intraoperative fracture rate was 2.9% and 13.6% in primary and revision settings, respectively. There were 136 humeral fractures, 60% of them occurred in revision RSAs, during the removal of the previous implant, and involved the shaft in the majority of cases (39%). Glenoid fractures were 51 and occurred mostly during the reaming of the glenoid. We observed 7 further related complications (rate of 4%) and 3 reoperations (rate of 1.5%). The outcome was satisfactory in the majority of cases. Conclusions: A comprehensive review on intraoperative fractures in reverse shoulder arthroplasties is presented. Results suggest favorable outcomes for all treatment methods, with a modest further complication rate. This investigation may aid in the treatment decision-making for these complications
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