302 research outputs found

    Wind shear estimation and wake detection by rotor loads - First wind tunnel verification

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    The paper describes a simple method for detecting presence and location of a wake affecting a downstream wind turbine operating in a wind power plant. First, the local wind speed and shear experienced by the wind turbine are estimated by the use of rotor loads and other standard wind turbine response data. Then, a simple wake deficit model is used to determine the lateral position of the wake with respect to the affected rotor. The method is verified in a boundary layer wind tunnel using two instrumented scaled wind turbine models, demonstrating its effectiveness

    Ziziphus lotus (L.) Lam. as a source of health promoting products: metabolomic profile, antioxidant and tyrosinase inhibitory activities

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    The methanolic extract of the stem bark of a wild species of jujube, Ziziphus lotus (L.) Lam., growing in Sicily, was chemically and biologically investigated. The chemical profile was defined by UHPLC-HR-ESI-Orbitrap/MS analysis whereas antioxidant and tyrosinase inhibitory activities were investigated by in vitro assays. The extract showed a high total phenolic and flavonoid content (TPC = 271.65 GAE/g and TFC = 188.11 RE/g extract). Metabolomic analysis revealed a rich phytocomplex characterized by phenols, cyclopeptide alkaloids, and triterpenoid saponins, some of which here detected for the first time. The mushroom tyrosinase inhibition assay displayed that the methanolic extract efficiently inhibits the monophenolase and diphenolase activity. Furthermore, the extract showed a strong ability to scavenge DPPH, a good Fe3+ reducing antioxidant power, in addition to a Fe2+ chelating activity. Taken together, these results suggest possible novel applications of wild jujube stem bark as a source of potential skin-care agents with several uses in pharmaceutical and cosmetic industries

    Detection of rotor imbalance, including root cause, severity and location

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    This paper presents a new way of detecting imbalances on wind turbine rotors, by using a harmonic analysis of the rotor response in the fixed frame. The method is capable of distinguishing among different root causes of the imbalance. In addition, the imbalance severity and location, i.e. the affected blade, can be identified. The automatic classification of the imbalance problem is obtained by using a neural network. The performance of the method is illustrated with the help of different fault scenarios, within a high-fidelity simulation environment

    Evaluation of a Pomegranate Peel Extract as an Alternative Means to Control Olive Anthracnose

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    Olive anthracnose is caused by different species of Colletotrichum spp. and may be regarded as the most damaging disease of olive fruit worldwide, greatly affecting quality and quantity of the productions. A pomegranate peel extract (PGE) proved very effective in controlling the disease. The extract had a strong in vitro fungicidal activity against Colletotrichum acutatum sensu stricto, was very effective in both preventive and curative trials with artificially inoculated fruit, and induced resistance in treated olive tissues. In field trials, PGE was significantly more effective than copper, which is traditionally used to control the disease. The highest level of protection was achieved by applying the extract in the early ascending phase of the disease outbreaks because natural rots were completely inhibited with PGE at 12 g/liter and were reduced by 98.6 and by 93.0% on plants treated with PGE at 6 and 3 g/liter, respectively. Two treatments carried out 30 and 15 days before the expected epidemic outbreak reduced the incidence of the disease by 77.6, 57.0, and 51.8%, depending on the PGE concentration. The analysis of epiphytic populations showed a strong antimicrobial activity of PGE, which sharply reduced both fungal and bacterial populations. Because PGE was obtained from a natural matrix using safe chemicals and did not have any apparent phytotoxic effect on treated olive fruit, it may be regarded as a safe and effective natural antifungal preparation to control olive anthracnose and improve olive productions

    Phytochemical constituents, antioxidant activity, and toxicity assessment of the aerial part extracts from the infraspecific taxa of Matthiola fruticulosa (Brassicaceae) endemic to Sicily

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    In a project designed to investigate the specific and infraspecific taxa of Matthiola endemic to Sicily (Italy) as new potential sources of bioactive compounds in this work, the infraspecific taxa of Matthiola fruticulosa were studied, namely, subsp. fruticulosa and subsp. coronopifolia. HPLC-PDA/ESI-MS and SPME-GC/MS analyses of hydroalcoholic extracts obtained from the aerial parts of the two subspecies led to the detection of 51 phenolics and 61 volatile components, highlighting a quite different qualitative-quantitative profile. The antioxidant properties of the extracts were explored through in vitro methods: 1,1-diphenyl-2-picrylhydrazyl (DPPH), reducing power and Fe2+ chelating activity assays. The results of the antioxidant tests showed that the extracts possess a different antioxidant ability: Particularly, the extract of M. fruticulosa subsp. fruticulosa exhibited higher radical scavenging activity than that of subsp. coronopifolia (IC50 = 1.25 ± 0.02 mg/mL and 2.86 ± 0.05 mg/mL), which in turn displayed better chelating properties (IC50 = 1.49 ± 0.01 mg/mL and 0.63 ± 0.01 mg/mL). Lastly, Artemia salina lethality bioassay was performed for toxicity assessment. The results of the bioassay showed lack of toxicity against brine shrimp larvae for both extracts. The data presented indicate the infraspecific taxa of M. fruticulosa as new and safe sources of antioxidant compounds

    Comparative Study on Phenolic Profile and Biological Activities of the Aerial Parts of Sinapis pubescens L. subsp. pubescens (Brassicaceae) Wild from Sicily (Italy)

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    This work aimed to investigate Sinapis pubescens subsp. pubescens spontaneously grown in Sicily (Italy) as new potential source of active metabolites; specifically, a comparative study on leaf, flower, and stem hydroalcoholic extracts was performed. Polyphenols were quantitatively determined by spectrophotometric methods and characterized by HPLC-PDA/ESI-MS; a total of 55 polyphenolic compounds were identified, highlighting considerably different qualitative-quantitative profiles. The extracts showed antioxidant activity, evaluated by in vitro assays; particularly, the leaf extract displayed the best radical scavenging activity (DPPH test) and reducing power, while the flower extract showed the greatest chelating activity. The antimicrobial properties of the extracts were investigated against bacteria and yeasts by standard methods; no antimicrobial activity was found against the strains tested. The extracts resulted to be non-toxic after preliminary toxicity evaluation by the Artemia salina lethality bioassay. The aerial parts of S. pubescens subsp. pubescens proved to be valuable sources of antioxidants for pharmaceutical and nutraceutical applications

    Image-guided multisession radiosurgery of skull base meningiomas

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    Background: The efficacy of single-session stereotactic radiosurgery (sSRS) for the treatment of intracranial meningioma is widely recognized. However, sSRS is not always feasible in cases of large tumors and those lying close to critically radiation-sensitive structures. When surgery is not recommended, multi-session stereotactic radiosurgery (mSRS) can be applied. Even so, the efficacy and best treatment schedule of mSRS are not yet established. The aim of this study is to validate the role of mSRS in the treatment of skull base meningiomas. Methods: A retrospective analysis of patients with skull base meningiomas treated with mSRS (two to five fractions) at the University of Messina, Italy, from 2008 to 2018, was conducted. Results: 156 patients met the inclusion criteria. The median follow-up period was 36.2 \ub1 29.3 months. Progression-free survival at 2-, 5-, and 10-years was 95%, 90%, and 80.8%, respectively. There were no new visual or motor deficits, nor cranial nerves impairments, excluding trigeminal neuralgia, which was reported by 5.7% of patients. One patient reported carotid occlusion and one developed brain edema. Conclusion: Multisession radiosurgery is an effective approach for skull base meningiomas. The long-term control is comparable to that obtained with conventionally-fractionated radiotherapy, while the toxicity rate is very limited

    Factors affecting outcome in frameless non-isocentric stereotactic radiosurgery for trigeminal neuralgia: A multicentric cohort study

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    Background: Stereotactic radiosurgery (SRS) is an effective treatment for trigeminal neuralgia (TN). Nevertheless, a proportion of patients will experience recurrence and treatment-related sensory disturbances. In order to evaluate the predictors of efficacy and safety of image-guided non-isocentric radiosurgery, we analyzed the impact of trigeminal nerve volume and the nerve dose/volume relationship, together with relevant clinical characteristics. Methods: Two-hundred and ninety-six procedures were performed on 262 patients at three centers. In 17 patients the TN was secondary to multiple sclerosis (MS). Trigeminal pain and sensory disturbances were classified according to the Barrow Neurological Institute (BNI) scale. Pain-free-intervals were investigated using Kaplan Meier analyses. Univariate and multivariate Cox regression analyses were performed to identify predictors. Results: The median follow-up period was 38 months, median maximal dose 72.4 Gy, median target nerve volume 25 mm3, and median prescription dose 60 Gy. Pain control rate (BNI I-III) at 6, 12, 24, 36, 48, and 60 months were 96.8, 90.9, 84.2, 81.4, 74.2, and 71.2%, respectively. Overall, 18% of patients developed sensory disturbances. Patients with volume 65 30 mm3 were more likely to maintain pain relief (p = 0.031), and low integral dose (< 1.4 mJ) tended to be associated with more pain recurrence than intermediate (1.4-2.7 mJ) or high integral dose (> 2.7 mJ; low vs. intermediate: log-rank test, \u3c72 = 5.02, p = 0.019; low vs. high: log-rank test, \u3c72 = 6.026, p = 0.014). MS, integral dose, and mean dose were the factors associated with pain recurrence, while re-irradiation and MS were predictors for sensory disturbance in the multivariate analysis. Conclusions: The dose to nerve volume ratio is predictive of pain recurrence in TN, and re-irradiation has a major impact on the development of sensory disturbances after non-isocentric SRS. Interestingly, the integral dose may differ significantly in treatments using apparently similar dose and volume constraints

    Management of major depression in outpatients attending a cancer centre: a preliminary evaluation of a multicomponent cancer nurse-delivered intervention

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    A novel nurse-delivered multicomponent intervention for major depressive disorder (MDD) in cancer outpatients was compared with usual care alone in a nonrandomised matched group design (n=30 per group). At the final 6-month outcome, 38.5% (95% CI, 5.4-57%) fewer patients in the intervention group still met the criteria for MDD
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