1,796 research outputs found

    Mechanical Performance of Fiber Reinforced Cement Composites Including Fully-Recycled Plastic Fibers

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    The use of virgin and recycled plastic macro fibers as reinforcing elements in construction materials has recently gained increasing attention from researchers. Specifically, recycled fibers have become more attractive owing to their large-scale availability, negligible cost, and low environmental footprint. In this work, we investigate the benefits related to the use of fully-recycled synthetic fibers as dispersed reinforcement in Fiber Reinforced Cement Composites (FRCCs). In light of the reference performance of FRCCs including virgin polypropylene (PP) fibers only, the mechanical response of composites reinforced with polyolefin filaments treated with a sol-gel silica coating and polyethylene terephthalate (PET)/polyethylene (PE) cylindrical draw-wire fibers is here assessed through three-point bending tests. Remarkably, recycled polyolefins lead to a notable enhancement in terms of peak strength and post-crack energy dissipation capability. This improvement is ascribed to both the flattened shape of fibers and the surface coating, which turns out to be very effective at strengthening the fiber-to-matrix bond. On the other hand, PET/PE fibrous reinforcement generally leads to a lower toughness, if compared to the virgin fibers. However, no reduction in terms of peak stress is evidenced. Balancing the significance of mechanical performance and environmental sustainability in the framework of a circular economy approach, both fully-recycled fibers at hand can be regarded as promising candidates for innovative structural application

    Critical Upper Limb Ischemia Due to Brachial Tourniquet in Misdiagnosed Thoracic Outlet Syndrome after Carpal Tunnel Decompression: A Case Report

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    We present the case of a 68-year-old woman, referred to our department for critical upper limb ischemia, which had occurred a few days after homolateral surgical ligamentotomy for carpal tunnel syndrome, diagnosed and confirmed by electromyography, and performed with a brachial tourniquet. The patient was later admitted for subsequent progressive necrosis of the first three fingers of the left hand, accompanied by signs of upper limb ischemia. An accessory cervical rib was identified, completely obliterating the subclavian artery distally at the origin of the suprascapular artery. A complete humeral artery occlusion was also found at the middle third of the humerus. The accessory rib was resected and the subclavian artery recanalized. A few days later, necrosis of the distal third of the first two fingers appeared and surgical resection was performed. Despite this chronic condition, the acute occlusion of collateral circles was probably induced by the brachial tourniquet. This represents a rare event, never previously reported in the literature: a case of critical upper limb ischemia due to a brachial tourniquet in a patient with misdiagnosed thoracic outlet syndrome. Until specific electrophysiological criteria for this syndrome can be found, attention should focus on history and clinical examination in patients with suspected carpal tunnel syndrome

    Practical Parallelization of Scientific Applications

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    Parallel waveform extraction algorithms for the Cherenkov Telescope Array Real-Time Analysis

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    The Cherenkov Telescope Array (CTA) is the next generation observatory for the study of very high-energy gamma rays from about 20 GeV up to 300 TeV. Thanks to the large effective area and field of view, the CTA observatory will be characterized by an unprecedented sensitivity to transient flaring gamma-ray phenomena compared to both current ground (e.g. MAGIC, VERITAS, H.E.S.S.) and space (e.g. Fermi) gamma-ray telescopes. In order to trigger the astrophysics community for follow-up observations, or being able to quickly respond to external science alerts, a fast analysis pipeline is crucial. This will be accomplished by means of a Real-Time Analysis (RTA) pipeline, a fast and automated science alert trigger system, becoming a key system of the CTA observatory. Among the CTA design key requirements to the RTA system, the most challenging is the generation of alerts within 30 seconds from the last acquired event, while obtaining a flux sensitivity not worse than the one of the final analysis by more than a factor of 3. A dedicated software and hardware architecture for the RTA pipeline must be designed and tested. We present comparison of OpenCL solutions using different kind of devices like CPUs, Graphical Processing Unit (GPU) and Field Programmable Array (FPGA) cards for the Real-Time data reduction of the Cherenkov Telescope Array (CTA) triggered data.Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.0589

    Dynamics of DiskMass Survey galaxies in refracted gravity

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    We test if Refracted Gravity (RG) can describe the dynamics of disk galaxies without resorting to dark matter. RG is a classical theory of gravity where the standard Poisson equation is modified by the gravitational permittivity, \epsilon, a universal monotonic function of the local mass density. We use the rotation curves and the vertical velocity dispersions of 30 galaxies in the DiskMass Survey (DMS) to determine \epsilon. RG describes the kinematic profiles with mass-to-light ratios consistent with SPS models, and disk thicknesses in agreement with observations, once observational biases are considered. Our results rely on setting the three free parameters of \epsilon for each galaxy. However, we show that the differences of these parameters from galaxy to galaxy could be ascribed to statistical fluctuations. We adopt an approximate method to find a single set of parameters that may properly describe the kinematics of the entire sample and suggest the universality of \epsilon. Finally, we show that the RG models of the individual rotation curves can only partly describe the radial acceleration relation (RAR). Evidently, the RG models underestimate the observed accelerations of 0.1-0.3 dex at low Newtonian accelerations. Another problem is the strong correlation, at much more than 5\sigma, between the residuals of the RAR models and three radially-dependent properties of galaxies, whereas the DMS data show a considerably less significant correlation, at more than 4\sigma, for only two of them. These correlations might originate the non-null intrinsic scatter of the RG models, at odds with the observed intrinsic scatter of galaxy samples different from DMS, which is consistent with 0. Further studies are required to assess if these discrepancies in the RAR originate from the DMS sample, which might not be ideal for deriving the RAR, or if they are genuine failures of RG.Comment: 36 pages, 22 figures, 7 tables, published in Astronomy & Astrophysics, Section 2. Astrophysical processes of Astronomy and Astrophysics; v2: minor corrections due to editorial process, notes added below the tables, arXiv references updated, italics removed from the titl

    Well-being in patients with schizophrenia, mood and personality disorders attending psychiatric services in the community. A controlled study

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    Background: Poor attention is paid by recent research to the prevalence of mental well-being in psychiatric patients and the comparison between groups with different diagnoses. Data suggest that the presence of mental illness does not necessarily mean the absence of well-being, particularly in stable outpatients. Methods: A consecutive series of 375 patients attending two community mental health centers was given the Mental Health Continuum Short Form (MHC-SF) and the Clinical Global Impression 鈥 Severity scale. Diagnoses were made after the MINI Neuropsychiatric Interview and a chart review of all relevant clinical information. The flourishing category and the three components of MHC-SF were used to rate well-being. A total of 274 controls were taken from the employees at a local firm. Results: The rates of flourishing mental health were: 33.1% schizophrenia, 36.6% bipolar disorder, 23.3% unipolar depression, 24.4% cluster B personality disorder, and 53.3% controls (p鈥<鈥0.001). The comparison of the three MHC components across diagnostic groups found that unipolar depression and cluster B personality patients had significantly lower scores compared to bipolar and schizophrenia patients. Flourishing mental health was detected more often in males than females (34.9% vs. 24.1% - p鈥<鈥0.05). For schizophrenia patients indices of well-being were better in those on depot medications. Conclusions: Psychiatric outpatients with major mental illness have lower rates of well-being compared to controls, although about one-third is flourishing. Patients with unipolar depression and cluster B personality disorder may deserve special attention when planning intervention for fostering well-being. Keywords: Well-being, Flourishing, Mental health, Schizophrenia, MHC-SF, Depressio

    Effects of antihypertensive drugs on carotid intima-media thickness: Focus on angiotensin II receptor blockers. A review of randomized, controlled trials

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    Carotid intima-media thickness (IMT) and plaques have been shown to have a strong continuous relationship with cardiovascular (CV) morbidity and mortality; therefore, carotid atherosclerosis, as assessed by ultrasonography, can be regarded as a reliable surrogate end-point for therapeutic interventions. In this survey, we report the results of 16 double blind, randomized, controlled studies comparing: 1) antihypertensive drugs versus placebo/no treatment (five trials including 3,215 patients); 2) different active antihypertensive drug regimens (five trials including 4,662 patients); 3) angiotensin-II receptor blockers (ARBs) versus other antihypertensive agents (six trials including 841 patients). Our main findings can be summarized as follows: I) Long-term antihypertensive treatment has a blunting effect on carotid IMT progression, regardless of types of drugs. II) Calcium-channel blockers (CCBs) are more effective than other antihypertensive drugs including diuretics, beta-blockers, and angiotensin converting-enzyme (ACE)-inhibitors in this blunting effect; III) the effect of ARBs compared to other antihypertensive regimens (mostly based on atenolol) on carotid atherosclerosis progression needs to be further elucidated, as a protective effect was demonstrated by some, but not all studies examined. Thus, further studies are needed to clarify the role of ARBs in this therapeutic area

    Mammographic breast density in infertile and parous women

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    BACKGROUND: Mammographic breast density is a useful marker for breast cancer risk, as breast density is considered one of the strongest breast cancer risk factors. The study objective was to evaluate and compare mammographic breast density in infertile and parous women, as infertility may be associated with high breast density and cancer occurrence. METHODS: This study evaluated mammographic breast density using two different systems, BIRADS and Boyd. A selected patient population of 151 women with primary infertility (case group) was compared to 154 parous women who had at least one previous pregnancy (control group). Both groups were premenopausal women aged 鈮 35. RESULTS: Evaluation of mammographic features showed that 66.9% of case group patients and 53.9% of control group patients were classified BIRADS-3/BIRADS-4; p < 0.05. Adjusted Odds ratio for the case group in the categories BIRADS-3/BIRADS-4 was 1.78 (95% CI: 1.10-2.89). Using the Boyd classification system, 53.6% of case group patients and 31.8% of control group patients were classified E/F; p < 0.05. Adjusted Odds ratio for case group patients in Boyd categories E/F was 2.05 (95 % CI: 1.07-3.93). CONCLUSIONS: Both systems yielded a higher percentage of increased breast density in the case group. Boyd and BIRADS classification systems indicate to what extend breast cancer lesions may be missed on mammography due to masking by dense tissue. Therefore, patients with a high BIRADS or Boyd score should undergo further investigation
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