2,308 research outputs found

    Recurrent glioma and crossed cerebellar diaschisis in a patient examined with 18F-DOPA and 18F-FDG PET/CT

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    Two years after resection of a left parietal glioma, a 46-year-old woman underwent F-FDG and F-DOPA brain PET/CT. FDG showed left parietal hypometabolism with crossed cerebellar diaschisis. No abnormally increased FDG activity was seen. F-DOPA PET/CT scan demonstrated focal left parietal uptake. Recurrent glioma was confirmed by surgical biopsy. F-DOPA may demonstrate abnormal amino acid metabolism in evaluation of recurrence of glioma

    Characterization of the ELIMED Permanent Magnets Quadrupole system prototype with laser-driven proton beams

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    Laser-based accelerators are gaining interest in recent years as an alternative to conventional machines [1]. In the actual ion acceleration scheme, energy and angular spread of the laser-driven beams are the main limiting factors for beam applications and different solutions for dedicated beam-transport lines have been proposed [2,3]. In this context a system of Permanent Magnet Quadrupoles (PMQs) has been realized [2] by INFN-LNS (Laboratori Nazionali del Sud of the Instituto Nazionale di Fisica Nucleare) researchers, in collaboration with SIGMAPHI company in France, to be used as a collection and pre-selection system for laser driven proton beams. This system is meant to be a prototype to a more performing one [3] to be installed at ELI-Beamlines for the collection of ions. The final system is designed for protons and carbons up to 60 MeV/u. In order to validate the design and the performances of this large bore, compact, high gradient magnetic system prototype an experimental campaign have been carried out, in collaboration with the group of the SAPHIR experimental facility at LOA (Laboratoire d'Optique Appliquée) in Paris using a 200 TW Ti:Sapphire laser system. During this campaign a deep study of the quadrupole system optics has been performed, comparing the results with the simulation codes used to determine the setup of the PMQ system and to track protons with realistic TNSA-like divergence and spectrum. Experimental and simulation results are good agreement, demonstrating the possibility to have a good control on the magnet optics. The procedure used during the experimental campaign and the most relevant results are reported here

    Numerical simulation of fluid structure interaction in free-surface flows: the WEC case

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    In this work we present a numerical framework to carry-out numerical simulations of fluid-structure interaction phenomena in free-surface flows. The framework employs a singlephase method to solve momentum equations and interface advection without solving the gas phase, an immersed boundary method (IBM) to represent the moving solid within the fluid matrix and a fluid structure interaction (FSI) algorithm to couple liquid and solid phases. The method is employed to study the case of a single point wave energy converter (WEC) device, studying its free decay and its response to progressive linear waves.E.Schillaci acknowledges the financial support of the Programa Torres Quevedo (PTQ2018- 010060). The work has also been supported by a competitive R+D project (PID2020-115837RBI00) of the Spanish Research Agency.Peer ReviewedPostprint (published version

    Usefulness of hybrid SPECT/CT for the 99mTc-HMPAO-labeled leukocyte scintigraphy in a case of cranial osteomyelitis

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    Cranial osteomyelitis is a potentially fatal lesion. White blood cell scanning (WBC) with 99mTc-hexamethylpropylene amine oxime (HMPAO) has proven highly sensitive and specific in the diagnosis and follow-up of patients with suspected osteomyelitis. In this report we show the usefulness of SPECT and transmission CT performed simultaneously using a hybrid imaging device for the functional anatomic mapping of soft tissue and cranial bone infections. 99mTc-HMPAO-labeled leukocytes scintigraphy was performed on an elderly diabetic man with an intracranial mass lesion and with suspected temporal bone infection. Planar scans were acquired 30 min, 4 h, and 24 h after injection. SPECT/CT was obtained 6 h after tracer injection, using a dual-head camera coupled with a low-power X-ray tube. The scintigraphic results were matched with the results of surgery and of clinical follow-up. The planar images alone were true-positives for abscess in this patient. SPECT/CT improves the accuracy of 99mTc-HMPAO scintigraphy especially in discriminating between soft-tissue and bone involvement. In fact, SPECT/CT also showed temporal bone osteomyelitis. This result indicates that SPECT/CT performed using a hybrid device can improve imaging with 99mTc-HMPAO-labeled leukocytes in patients with suspected osteomyelitis by providing accurate anatomic localization and precise definition of the extent of infection

    Comparison of the immune response of Galleria mellonella and Rhynchophorus ferrugineus after infection with the entomopathogenic nematode Steinernema carpocapsae

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    The red palm weevil, Rhynchophorus ferrugineus (Olivier 1790) (Coleoptera: Curculionidae), a pest of palm trees, and Galleria mellonella L. (Lepidoptera: Pyralidae), a pest of beehives, were used as models to deepen our understanding of the host-entomopathogenic nematode relationship. The effects of the entomopathogenic nematode Steinernema carpocapsae (Nematoda: Steinernematidae) on the immune activity of R. ferrugineus and G. mellonella larvae were compared. The ability to complete the life cycle of S. carpocapsae in the two insects was also evaluated. Although S. carpocapsae is effective in the biological control of the red weevil, it is not able to complete its cycle within the host, whereas the same nematode successfully reproduces in G. mellonella. On the basis of previous laboratory data and a systematic literature review, the nematode-induced effects on the immune response of the Coleoptera and the Lepidoptera were compared. In particular, the immunocompetent haemocyte population (number and cell types), the activity of the prophenoloxidase- phenoloxidase system (proPO) and finally the inhibition and proliferation of the Gram-negative symbiont bacterium Xenorhabdus nematophila (Enterobacteraceae) were analysed

    Cerebral plasticity in acute vestibular deficit

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    The aim of this study was to analyze the effect of acute vestibular deficit on the cerebral cortex and its correlation with clinical signs and symptoms. Eight right-handed patients affected by vestibular neuritis, a purely peripheral vestibular lesion, underwent two brain single photon emission computed tomography (SPECT) in 1 month. The first SPECT analysis revealed reduced blood flow in the temporal frontal area of the right hemisphere in seven of eight patients, independent of the right/left location of the lesion. The alteration was present always in the right, non-dominant hemisphere and was reversible in some patients 1 month after the onset, together with attenuation of signs and symptoms. It may be hypothesized that the transient reduction of cortical blood flow and subsequently of cortical activity in the non-dominant hemisphere, also the expression of cerebral plasticity, may serve as a defense mechanism aimed to attenuate the vertigo symptom

    Indium(111) pentetreotide single photon emission computed tomography (In-111 pentetreotide SPECT): a new technique to evaluate somatostatin receptors in chordomas

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    Chordomas are rare neoplasms originating along the neuraxis. Although they do not usually show cytological atypia, metastases have been reported in 30 per cent of cases. Survival rates in cases of skull base locations are low, and local recurrence is common after local excision. Radiation therapy is used in post-operative treatment and proton radiation therapy as the primary treatment. In the present paper we present the case of a 50-year-old Caucasian man affected by chordoma of the clivus, with liver and chest metastases, relapsed after several surgical local excisions, to discuss improvements in therapeutic and imaging techniques. Indium(III) (In-III) pentetreotide single photon emission computed tomography (SPECT) was employed to assess the presence of somatostatin receptors and to treat the tumour with radiolabelled Y-90-DOTA-lanreotide. Imaging, performed 2 months afterwards, showed stable disease in the lungs but a local progression in the metastases, in comparison with pre-treatment uptake. These data suggest the usefulness of radiolabelled somatostatin analogues in the diagnosis and therapy of chordomas

    Prognostic value of18 f-choline pet/ct in patients with metastatic castration-resistant prostate cancer treated with radium-223

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    We aimed to investigate the role of positron emission computed tomography (PET/CT) with F-18-choline for predicting the outcome of metastatic castration-resistant prostate cancer (mCRPC) submitted to treatment with Radium-223 (Ra-223-therapy). Clinical records of 20 mCRPC patients submitted to PET/CT with F-18-choline before Ra-223-therapy were retrospectively evaluated. The following PET-derived parameters were calculated: number of lesions, maximum and mean standardized uptake values (SUVmax, SUVmean), lean body mass corrected SUV peak (SULpeak), metabolic tumor volume (MATV), and total lesion activity (TLA). After Ra-223-therapy, all patients underwent regular follow-up until death. The predictive power of clinical and PET-derived parameters on overall survival (OS) was assessed by Kaplan-Meier analysis and the Cox proportional hazard method. All the patients showed F-18-choline-avid lesions at baseline PET/CT. Among the enrolled subjects, eleven (55%) completed all the six scheduled cycles of Ra-223-therapy; seven (35%) were responders according to imaging and biochemical parameters. Mean OS was 12.7 +/- 1.4 months: by Kaplan-Meier analysis, number of lesions, PSA level and TLA were significantly correlated with OS. In multivariate Cox analysis, TLA remained the only significant predictor of survival (p = 0.003; hazard ratio = 7.6, 95% confidence interval = 1.9-29.5 months). F-18-choline PET may be useful for patients' stratification before Ra-223-therapy. In particular, high metabolically active tumor burden (i.e., TLA) was predictive of poor outcome

    Climate and environmental data contribute to the prediction of grain commodity prices using deep learning

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    Background: Grain commodities are important to people's daily lives and their fluctuations can cause instability for households. Accurate prediction of grain prices can improve food and social security. Methods & Materials: This study proposes a hybrid Long Short-Term Memory (LSTM)-Convolutional Neural Network (CNN) model to forecast weekly oat, corn, soybean and wheat prices in the United States market. The LSTM-CNN is a multivariate model that uses weather data, macroeconomic data, commodities grain prices and snow factors, including Snow Water Equivalent (SWE), snowfall and snow depth, to make multistep ahead forecasts. Results: Of all the features, the snow factor is used for the first time for commodity price forecasting. We used the LSTM-CNN model to evaluate the 5, 10, 15 and 20 weeks ahead forecasting and this hybrid model had the lowest Mean Squared Error (MSE) at 5, 10 and 15 weeks ahead of prediction. In addition, Shapley values were calculated to analyse the feature contribution of the LSTM-CNN model when forecasting the testing set. Based on the feature contribution, SWE ranked third, fifth and seventh in feature importance in the 5-week ahead forecast for corn, oats and wheat, respectively, and 7–8 places higher than total precipitation, indicating the potential use of SWE in grain price forecasting. Conclusion: The hybrid multivariate LSTM-CNN model outperformed other models and the newly involved climate data, SWE, showed the research potential of using snow as an input variable to predict grain prices over a multistep ahead time horizon
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