433 research outputs found

    Visual salience of the stop signal affects the neuronal dynamics of controlled inhibition

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    The voluntary control of movement is often tested by using the countermanding, or stop-signal task that sporadically requires the suppression of a movement in response to an incoming stop-signal. Neurophysiological recordings in monkeys engaged in the countermanding task have shown that dorsal premotor cortex (PMd) is implicated in movement control. An open question is whether and how the perceptual demands inherent the stop-signal affects inhibitory performance and their underlying neuronal correlates. To this aim we recorded multi-unit activity (MUA) from the PMd of two male monkeys performing a countermanding task in which the salience of the stop-signals was modulated. Consistently to what has been observed in humans, we found that less salient stimuli worsened the inhibitory performance. At the neuronal level, these behavioral results were subtended by the following modulations: when the stop-signal was not noticeable compared to the salient condition the preparatory neuronal activity in PMd started to be affected later and with a less sharp dynamic. This neuronal pattern is probably the consequence of a less efficient inhibitory command useful to interrupt the neural dynamic that supports movement generation in PMd

    Psicopatologia da vergogna. Esperienze cliniche

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    none1noVengono trattati casi clinici affetti da patologia da vergognanoneR. PaniR. Pan

    Lo shopping compulsivo... tra i "nuovi sintomi"

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    none2Lo shopping compulsivo tra i nuovi sintominoneRoberto Pani; Roberta BiolcatiRoberto Pani; Roberta Biolcat

    automatic detection of complete and measurable cardiac cycles in antenatal pulsed wave doppler signals

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    Abstract Background and objective Pulsed-wave Doppler (PWD) echocardiography is the primary tool for antenatal cardiological diagnosis. Based on it, different measurements and validated reference parameters can be extracted. The automatic detection of complete and measurable cardiac cycles would represent a useful tool for the quality assessment of the PWD trace and the automated analysis of long traces. Methods This work proposes and compares three different algorithms for this purpose, based on the preliminary extraction of the PWD velocity spectrum envelopes: template matching, supervised classification over a reduced set of relevant waveshape features, and supervised classification over the whole waveshape potentially representing a cardiac cycle. A custom dataset comprising 43 fetal cardiac PWD traces (174,319 signal segments) acquired on an apical five-chamber window was developed and used for the assessment of the different algorithms. Results The adoption of a supervised classifier trained with the samples representing the upper and lower envelopes of the PWD, with additional features extracted from the image, achieved significantly better results (p Conclusions The results reveal excellent detection performance, suggesting that the proposed approach can be adopted for the automatic analysis of long PWD traces or embedded in ultrasound machines as a first step for the extraction of measurements and reference clinical parameters

    Similar reduction of cholesterol-adjusted Vitamin E serum levels in simple steatosis and non-alcoholic steatohepatitis

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    OBJECTIVES: Reduced vitamin E levels have been reported in patients with non-alcoholic steatohepatitis (NASH), but no conclusive data on patients with simple steatosis (SS) are available. Aim of this study was to investigate the association betweenserum vitamin E levels and SS. METHODS: A cohort of 312 patients with cardio-metabolic risk factors was screened for liver steatosis by ultrasonography (US). We reasonably classified as SS patients with US-fatty liver, normal liver function tests (LFTs) and with Cytokeratin 18 o246 mIU/ml. Liver biopsy was performed in 41 patients with US-fatty liver and persistent elevation of LFTs (46 months). Serum cholesterol-adjusted vitamin E (Vit E/chol) levels were measured. RESULTS: Mean age was 53.9±12.5 years and 38.4% were women. Non-alcoholic fatty liver disease (NAFLD) was detected at US in 244 patients; of those 39 had biopsy-proven NASH and 2 borderline NASH. Vit E/chol was reduced in both SS (3.4±2.0, Po0.001), and NASH (3.5±2.1, P=0.006) compared with non-NAFLD patients (4.8±2.0 μmol/mmol chol). No difference was found between SS and NASH (P=0.785). After excluding patients with NASH, a multivariable logistic regression analysis found that Vit E/chol (odds ratio (OR): 0.716, 95% confidence interval (CI) 0.602–0.851, Po0.001), alanine aminotransferase (ALT, OR: 1.093, 95% CI 1.029–1.161, P=0.004), body mass index (OR: 1.162, 95% CI 1.055–1.279, P=0.002) and metabolic syndrome (OR: 5.725, 95% CI 2.247–14.591, Po0.001) were factors independently associated with the presence of SS. CONCLUSIONS: Reduced vitamin E serum levels are associated with SS, with a similar reduction between patients with SS and NASH, compared with non-NAFLD patients. Our findings suggest that the potential benefit of vitamin E supplementation should be investigated also in patients with SS

    Natural phenolic inhibitors of trichothecene biosynthesis by the wheat fungal pathogen <i>Fusarium culmorum</i>: a computational insight into the structure-activity relationship

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    A model of the trichodiene synthase (TRI5) of the wheat fungal pathogen and type-B trichothecene producer Fusarium culmorum was developed based on homology modelling with the crystallized protein of F. sporotrichioides. Eight phenolic molecules, namely ferulic acid 1, apocynin 2, propyl gallate 3, eugenol 4, Me-dehydrozingerone 5, eugenol dimer 6, magnolol 7, and ellagic acid 8, were selected for their ability to inhibit trichothecene production and/or fungal vegetative growth in F. culmorum. The chemical structures of phenols were constructed and partially optimised based on Molecular Mechanics (MM) studies and energy minimisation by Density Functional Theory (DFT). Docking analysis of the phenolic molecules was run on the 3D model of F. culmorum TRI5. Experimental biological activity, molecular descriptors and interacting-structures obtained from computational analysis were compared. Besides the catalytic domain, three privileged sites in the interaction with the inhibitory molecules were identified on the protein surface. The TRI5-ligand interactions highlighted in this study represent a powerful tool to the identification of new Fusarium-targeted molecules with potential as trichothecene inhibitors

    Gamma emission tomosynthesis based on an automated slant hole collimation system

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    The imaging capabilities of radioisotope molecular imaging systems are limited by their ring geometry and by the object-to-detector distance, which impairs spatial resolution, efficiency and image quality. These detection capabilities could be enhanced by performing acquisitions with dedicated gamma cameras placed in close proximity to the object that has to be examined. The main aim of this work is to develop a compact camera suitable for detecting small and low-contrast lesions, with a higher detection efficiency than conventional SPECT, through a gamma emission tomosynthesis method. In this contribution a prototype of a new automated slant hole collimator, coupled to a small Field of View (FoV) gamma camera, is presented. The proposed device is able to acquire planar projection images at different angles without rotating around the patient body; these projection images are then three-dimensional reconstructed. Therefore, in order to perform the volumetric reconstruction of the studied object, the traditional Back Projection (BP) reconstruction is compared with the Shift And Add (SAA) method. In order to verify the effectiveness of the technique and to test the image reconstruction algorithms, a Monte Carlo simulation, based on the GEANT4 code, was implemented. The method was also validated by a set of experimental measurements. The discussed device is designed to work in patient proximity for detecting lesions placed at a distances ranged from 0 to 8 cm, thus allowing few millimeters planar resolutions and sagittal resolution of about 2 cm. The new collimation method implies high-resolution capabilities demonstrated by reconstructing the projection images through the BP and the SAA methods. The latter is simpler than BP and produces comparable spatial resolutions with respect to the traditional tomographic method, while preserving the image counts. © 2015 IOP Publishing Ltd and Sissa Medialab srl

    Holographic collisions in confining theories

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    We study the gravitational dual of a high-energy collision in a confining gauge theory. We consider a linearized approach in which two point particles traveling in an AdS-soliton background suddenly collide to form an object at rest (presumably a black hole for large enough center-of-mass energies). The resulting radiation exhibits the features expected in a theory with a mass gap: late-time power law tails of the form t −3/2, the failure of Huygens" principle and distortion of the wave pattern as it propagates. The energy spectrum is exponentially suppressed for frequencies smaller than the gauge theory mass gap. Consequently, we observe no memory effect in the gravitational waveforms. At larger frequencies the spectrum has an upward-stairway structure, which corresponds to the excitation of the tower of massive states in the confining gauge theory. We discuss the importance of phenomenological cutoffs to regularize the divergent spectrum, and the aspects of the full non-linear collision that are expected to be captured by our approach

    Diagnostic Value of the Early Heart-to-Mediastinum Count Ratio in Cardiac 123I-mIBG imaging for Parkinson's Disease

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    Early diagnosis of Parkinson's disease (PD) is of primary importance. The delayed (3-4 h after injection) Iodine-123-Metaiodobenzylguanidine (123I-mIBG) scintigraphy has been proven to be effective in early differential diagnosis for Lewy body disease. But early imaging (15-30 min after injection) has only been marginally studied for its possible diagnostic role. In this prospective study a thresholdfor the early Heart-to-Mediastinum (H/M) count ratio has been investigated, obtaining a diagnostic accuracy analogous to conventional, delayed imaging
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