520 research outputs found

    Herbage Allowance and Nitrogen Fertilization Effects on Morphological Characteristics of \u3ci\u3ePaspalum notatum\u3c/i\u3e FlĂĽgge

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    The grazing study was conducted at the Estação Experimental Agronomica – UFRGS, 30o S, on a native pasture, to evaluate the leaf area index and structural morphological traits of bahiagrass (Paspalum notatum Fl.), within the requirements of a Central Composite Rotatable experimental design, providing for equal precision, with two blocks, encompassing two factors at five levels each, namely: Herbage Allowance (HA) = 4.0; 5.5; 9.0; 12.5 and 14.0 kg green dry matter per 100 kg liveweight per day (% LW), in association with Nitrogen (N) fertilization levels of 0; 30; 100; 170 and 200 kg ha-1 as urea, The leaf length and leaf area index (LAI) were increased as HA and N levels increased. The tiller density was increased at higher HA where the N contribution showed to be more effective. More lenient grazing also increased leaf life span and leaf lamina length, while N promoted canopy density and reduced leaf life span and number of leaves per tiller. The higher LAI values developed were accomplished by reduced tiller densities that supported small number of leaves per tiller, with increased leaf sizes

    Articulated blade tip devices for load alleviation on wind turbines

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    This paper investigates the load alleviation capabilities of an articulated tip device, where the outermost portion of the blade can rotate with respect to the rest of the blade. Passive, semi-passive and active solutions are developed for the tip rotation. In the passive and semi-passive configurations tip pitching is mainly driven by aerodynamic loads, while for the active case the rotation is obtained with an actuator commanded by a feedback control law. Each configuration is analyzed and tested using a high-fidelity aeroservoelastic simulation environment, by considering standard operative conditions as well as fault situations. The potential benefits of the proposed blade tip concepts are discussed in terms of performance and robustness

    Tyr78Phe Transthyretin Mutation with Predominant Motor Neuropathy as the Initial Presentation

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    Transthyretin (TTR) amyloidosis, the most frequent form of hereditary amyloidosis, is caused by dominant mutations in the TTR gene. More than 100 mutations have been identified. Clinical manifestations of TTR amyloidosis are usually induced by extracellular amyloid deposition in several organs. The major neurological manifestation is motor-sensory neuropathy associated with dysautonomic impairment. Here, we describe a 63-year-old man who came to our institution due to a suspected motor neuron disease. During a 4-year follow-up period, he underwent extensive clinical examination, electromyographic studies, sural nerve biopsy and TTR gene analysis by direct sequencing. Despite the predominant motor involvement, the detailed clinical examination also showed some mild sensory and dysautonomic signs. In addition, his clinical and family history included multiorgan disorders, such as carpal tunnel syndrome, as well as conditions with cardiac, renal, eye, and hepatic involvement. The sural nerve biopsy disclosed amyloid deposition, and the sequence analysis of the TTR gene detected a heterozygous Tyr78Phe substitution. The TTR gene variant found in our patient had only been described once so far, in a French man of Italian origin presenting with late-onset peripheral neuropathy and bilateral carpal tunnel syndrome. The predominant motor involvement presented by our patient is an uncommon occurrence and demonstrates the clinical heterogeneity of TTR amyloidosis

    Hybrid fibroin/polyurethane small-diameter vascular grafts: from fabrication to in vivo preliminary assessment

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    To address the need of alternatives to autologous vessels for small-calibre vascular applications (e.g. cardiac surgery), a bio-hybrid semi-degradable material composed of silk fibroin (SF) and polyurethane (Silkothane (R)) was herein used to fabricate very small-calibre grafts (o(in) = 1.5 mm) via electrospinning. Bio-hybrid grafts were in vitro characterized in terms of morphology and mechanical behaviour, and compared to similar grafts of pure SF. Similarly, two native vessels from a rodent model (abdominal aorta and vena cava) were harvested and characterized. Preliminary implants were performed on Lewis rats to confirm the suitability of Silkothane (R) grafts for small-calibre applications, specifically as aortic insertion and femoral shunt. The manufacturing process generated pliable grafts consisting of a randomized fibrous mesh and exhibiting similar geometrical features to rat aortas. Both Silkothane (R) and pure SF grafts showed radial compliances in the range from 1.37 +/- 0.86 to 1.88 +/- 1.01% 10(-2) mmHg(-1), lower than that of native vessels. The Silkothane (R) small-calibre devices were also implanted in rats demonstrating to be adequate for vascular applications; all the treated rats survived the surgery for three months after implantation, and 16 rats out of 17 (94%) still showed blood flow inside the graft at sacrifice. The obtained results lay the basis for a deeper investigation of the interaction between the Silkothane (R) graft and the implant site, which may deal with further analysis on the potentialities in terms of degradability and tissue formation, on longer time-points

    Feasibility study on 3D image reconstruction from 2D orthogonal cine-MRI for MRI-guided radiotherapy.

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    INTRODUCTION: In-room MRI is a promising image guidance strategy in external beam radiotherapy to acquire volumetric information for moving targets. However, limitations in spatio-temporal resolution led several authors to use 2D orthogonal images for guidance. The aim of this work is to present a method to concurrently compensate for non-rigid tumour motion and provide an approach for 3D reconstruction from 2D orthogonal cine-MRI slices for MRI-guided treatments. METHODS: Free-breathing sagittal/coronal interleaved 2D cine-MRI were acquired in addition to a pre-treatment 3D volume in two patients. We performed deformable image registration (DIR) between cine-MRI slices and corresponding slices in the pre-treatment 3D volume. Based on an extrapolation of the interleaved 2D motion fields, the 3D motion field was estimated and used to warp the pre-treatment volume. Due to the lack of a ground truth for patients, the method was validated on a digital 4D lung phantom. RESULTS: On the phantom, the 3D reconstruction method was able to compensate for tumour motion and compared favourably to the results of previously adopted strategies. The difference in the 3D motion fields between the phantom and the extrapolated motion was 0.4 ± 0.3 mm for tumour and 0.8 ± 1.5 mm for whole anatomy, demonstrating feasibility of performing a 3D volumetric reconstruction directly from 2D orthogonal cine-MRI slices. Application of the method to patient data confirmed the feasibility of utilizing this method in real world scenarios. CONCLUSION: Preliminary results on phantom and patient cases confirm the feasibility of the proposed approach in an MRI-guided scenario, especially for non-rigid tumour motion compensation

    Low-dose oral imatinib in the treatment of systemic sclerosis interstitial lung disease unresponsive to cyclophosphamide: a phase II pilot study.

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    NTRODUCTION: Pulmonary involvement represents a major cause of death of systemic sclerosis (SSc) patients. Recent data suggest that tyrosine kinase inhibitors, such as imatinib, may be a therapeutic option for SSc patients. However, preliminary published clinical trials were inconclusive about imatinib efficacy and showed side effects. The purpose of this study was to verify efficacy and tolerability of low-dose imatinib on interstitial lung disease in a cohort of SSc patients unresponsive to cyclophosphamide therapy. METHODS: Thirty consecutive SSc patients with active pulmonary involvement, unresponsive to cyclophosphamide, were treated with imatinib 200 mg/day for 6 months followed by a 6-month follow-up. A "good response" was defined as an increase of forced vital capacity (FVC) by more of 15% and/or increase of diffusing capacity of carbon monoxide (DLCO) >15% and PaO2 > 90% of initial value and high-resolution computed tomography (HRCT)-scan pattern unchanged or improved. RESULTS: Twenty-six patients completed the study. Three patients died and one patient was lost to follow-up. Four patients (15.32%) had a good response, 7 worsened and 15 had a stabilized lung disease. Overall, 19 (73.07%) patients had an improved or stabilized lung disease. After a 6-month follow-up, 12 (54.5%) of the 22 patients showed an improved or stabilized lung disease. CONCLUSIONS: Lung function was stabilized in a large proportion of patients unresponsive to cyclophosphamide therapy and a beneficial outcome emerged from the analysis of HRCT lung scans. There was no significant improvement of skin involvement, and the low dose was well tolerated. These data provide useful suggestions to design future randomized clinical trials for SSc therapeutics

    The PARIS cluster coupled to the BaFPro electronic module: data analysis from the NRF experiment at the Îł\gammaELBE facility

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    International audience; The first cluster of the constructed PARIS calorimeter was assembled and tested atthe ELBE facility at HZDR, Dresden, Germany. The experiment was aimed at the evaluationof the performance of each detector separately as well as the whole PARIS cluster with discreteγ\gamma-ray energies seen by the PARIS ranging up to 8.9 MeV. As the detectors use phoswichconfiguration, with 2'' x 2'' x 2'' LaBr3(Ce) crystal coupled to 2'' x 2'' x 6'' NaI(Tl) one, greatcare must be taken during the data analysis process to obtain the best possible values for energyresolution. Two algorithms for data transformation from matrices created with slow vs fastpulse shaping to energy spectra were tested from which one was chosen for further analysis. Analgorithm for adding back energies of γ\gamma-rays scattered inside the cluster was prepared, as well.Energy resolution for γ\gamma-rays in 2–8 MeV range was estimated and is presented in this paper
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