169 research outputs found

    Effects of transcranial alternating current stimulation on repetitive finger movements in healthy humans

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    Transcranial alternating current stimulation (tACS) is a noninvasive neurophysiological technique that can entrain brain oscillations. Only few studies have investigated the effects of tACS on voluntary movements. We aimed to verify whether tACS, delivered over M1 at beta and gamma frequencies, has any effect on repetitive finger tapping as assessed by means of kinematic analysis. Eighteen healthy subjects were enrolled. Objective measurements of repetitive finger tapping were obtained by using a motion analysis system. M1 excitability was assessed by using single-pulse TMS and measuring the amplitude of motor-evoked potentials (MEPs). Movement kinematic measures and MEPs were collected during beta, gamma, and sham tACS and when the stimulation was off. Beta tACS led to an amplitude decrement (i.e., progressive reduction in amplitude) across the first ten movements of the motor sequence while gamma tACS had the opposite effect. The results did not reveal any significant effect of tACS on other movement parameters, nor any changes in MEPs. These findings demonstrate that tACS modulates finger tapping in a frequency-dependent manner with no concurrent changes in corticospinal excitability. The results suggest that cortical beta and gamma oscillations are involved in the motor control of repetitive finger movements

    The Meandering Current Mobility Model and its impact on Underwater Mobile Sensor Networks

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    Underwater mobile acoustic sensor networks are promising tools for the exploration of the oceans. These networks require new robust solutions for fundamental issues such as: localization service for data tagging and networking protocols for communication. All these tasks are closely related with connectivity, coverage and deployment of the network. A realistic mobility model that can capture the physical movement of the sensor nodes with ocean currents gives better understanding on the above problems. In this paper, we propose a novel physically-inspired mobility model which is representative of underwater environments. We study how the model affects a range-based localization protocol, and its impact on the coverage and connectivity of the network under different deployment scenarios

    Pd-catalyzed Reductions in Deep Eutectic Solvents by Using Aluminum and Water as Hydrogen Source

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    The reduction of organic functional groups, using metal-catalyzed hydrogenations, is one of the most employed strategy in organic chemistry for the synthesis of both fine and bulk chemicals.[1] Hydrogen is an explosive gas and its production needs extensive energy and generates a considerable amount of carbon dioxide. Therefore, the development of cost-effective reduction methods that use safe reagents, environmentally-friendly solvents and prevent or minimize waste formation represents a challenge of great interest in sustainable chemistry. As part of our ongoing efforts in the discovery of sustainable synthetic methodologies,[2] an alternative and safe palladium-catalyzed hydrogenation reaction in Deep Eutectic Solvents (DESs) is here described.[3] The use of aluminum powder in combination with water and a base in DESs, results in an environmentally-responsible system for the controlled in-situ generation of hydrogen. Our optimized protocol is effective for the reduction of a wide range of functional groups, containing C–C, C–N, C–O, N–O multiple bonds as well as for the dearomatization of (hetero)aromatic compounds, and leads to the desired products in yield up-to 99%. The simplicity, cost, tunability, scalability and the environmentally benign character of both catalytic system and DESs, offer numerous advantages over the currently available methods that employ external and dangerous H2 source and harsh, volatile organic solvents

    A Glycerol-Based Deep Eutectic Solvent as Natural Medium and Organic Reductant for Homocoupling of (Hetero)Aryl Chlorides: a Green Route to 2,2’-Bipyridine and Biaryl Scaffolds

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    A glycerol-based Deep Eutectic Solvent (DES) enables the Pd-catalyzed activation of (hetero)arylchlorides and promotes the formation of 2,2’-bipiyridines and biaryls through an Ullmann-type homocoupling in smooth experimental conditions (80 °C) with Ca(OH)2 as a green base and Pd/C as heterogeneous catalyst. Noteworthy, the coupling does not need the addition of external reducing agents, like metals, since the glycerol present in the DES acts as a safe and green organic reductant. The heterogeneous catalytic system (DES-Pd/C) showed to be easily recyclable and has been applied to the sustainable synthesis of the Abametapir drug

    Gas-Free Amino- and Alkoxycarbonylation of Aryl Iodides in a Bioinspired Deep Eutectic Solvent with Mo(CO)6 as a Safe CO Source

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    The Pd-catalyzed amino- and alkoxycarbonylation of aryl iodides has been exploited, for the first time, in a bioinspired Deep Eutectic Solvent and under gas-free conditions, by using Mo(CO)6 as the CO source. The method allows for the preparation of carboxylic amides and esters in high yields (up to 99%), short reaction time (2 h) and under mild reaction conditions (80 °C), with a low catalyst loading (2.5 mol%). Noteworthy, in the case of N-hexylbenzamide, it has been demonstrated that both the catalyst and DES can be used for four consecutive runs, with a moderate decrease of catalytic efficiency. The methodology has been also applied to the preparation of an Active Pharmaceutical Ingredient used for the treatment of human scabies and lice

    Bradykinesia and dystonia

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    Background: Bradykinesia has been reported in patients with dystonia. Despite this, the pathophysiological mechanisms of bradykinesia in dystonia remain largely unknown. Methods: We here performed a comprehensive literature search and reviewed clinical and experimental studies on bradykinesia in patients with dystonia. Results: Many studies have documented the presence of bradykinesia in patients with idiopathic and inherited isolated dystonia, regardless of the presence of parkinsonism. In addition, bradykinesia has been observed as a side effect in dystonic patients who have undergone deep brain stimulation, in those with functional dystonia as well as in those with combined dystonia, e.g., dystonia-parkinsonism. These clinical and experimental findings support the hypothesis that dysfunction in a brain network involving the basal ganglia, primary sensorimotor cortex, and cerebellum may play a key role in the pathophysiology of both bradykinesia and dystonia. Conclusion: Bradykinesia is frequently observed in dystonia. We may gain insights into the pathophysiological underpinnings of two distinct movement disorders by investigating this issue. Furthermore, a deeper understanding of bradykinesia in dystonia may have terminological implications in this field

    May Bradykinesia Features Aid in Distinguishing Parkinson's Disease, Essential Tremor, And Healthy Elderly Individuals?

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    Background: Bradykinesia is the hallmark feature of Parkinson's disease (PD); however, it can manifest in other conditions, including essential tremor (ET), and in healthy elderly individuals. Objective: Here we assessed whether bradykinesia features aid in distinguishing PD, ET, and healthy elderly individuals. Methods: We conducted simultaneous video and kinematic recordings of finger tapping in 44 PD patients, 69 ET patients, and 77 healthy elderly individuals. Videos were evaluated blindly by expert neurologists. Kinematic recordings were blindly analyzed. We calculated the inter-raters agreement and compared data among groups. Density plots assessed the overlapping in the distribution of kinematic data. Regression analyses and receiver operating characteristic curves determined how the kinematics influenced the likelihood of belonging to a clinical score category and diagnostic group. Results: The inter-rater agreement was fair (Fleiss K = 0.32). Rater found the highest clinical scores in PD, and higher scores in ET than healthy elderly individuals (p < 0.001). In regard to kinematic analysis, the groups showed variations in movement velocity, with PD presenting the slowest values and ET displaying less velocity than healthy elderly individuals (all ps < 0.001). Additionally, PD patients showed irregular rhythm and sequence effect. However, kinematic data significantly overlapped. Regression analyses showed that kinematic analysis had high specificity in differentiating between PD and healthy elderly individuals. Nonetheless, accuracy decreased when evaluating subjects with intermediate kinematic values, i.e., ET patients. Conclusion: Despite a considerable degree of overlap, bradykinesia features vary to some extent in PD, ET, and healthy elderly individuals. Our findings have implications for defining bradykinesia and categorizing patients

    Atrial Fibrillation Ablation: A Single Center Comparison Between Remote Magnetic Navigation, Cryoballoon and Conventional Manual Pulmonary Vein Isolation

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    Contains fulltext : 88398.pdf (publisher's version ) (Open Access)BACKGROUND: The aim of the study was to compare in our center the effect of different ablation techniques on intermediate term freedom from atrial fibrillation (AF) or atrial tachycardia (AT) in patients affected by refractory AF. METHODS AND RESULTS: We retrospectively selected 94 patients who underwent AF ablation in our electrophysiological laboratory from June 2007 to December 2009. 29 patients underwent manual circumferential pulmonary vein isolation (mCPVI), 35 underwent remote magnetic navigation assisted CPVI (rmtCPVI) and 30 cryoballoon CPVI (cCPVI). Antiarrhythmic drugs were systematically stopped 2 months after the procedure (end of the "blanking period"). At a mean follow-up of 12,64 +/- 6,41 months (range 2-31), the success rate for mCPVI group was 65.5% (19 patients), 66.7 % (20 patients) for the rmtCPVI group and 65.7 % (23 patients) for the cCPVI group (p = 0.625). Procedural and fluoroscopy times were significantly reduced in the cCPVI group (both p < 0.001). Univariate Cox regression showed that no clinical variables were independently associated with recurrence. CONCLUSIONS: In our center's experience cCPVI and rmtCPVI have been demonstrated to be as effective as mCPVI. cCPVI seemed to be associated with lower procedural and fluoroscopy times

    Do Italian consumers value health claims on extra-virgin olive oil?

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    The present study aims to extend the existing literature on EVOO consumers by assessing the importance of health claims in selecting EVOO products by jointly accounting for consumer preferences for the many search, experience, and credence attributes potentially available on EVOO, as well as by accounting for attitudinal and psychographic individual characteristics which affect consumer decision to prefer products with health claims over conventional ones (i.e. subjective nutritional knowledge, nutritional knowledge, nutritional importance, attitudes towards using food as a medicine, general health interest). The latter characteristics play a pivotal role in individual decisions to consider health claims when purchasing food, as indicated in the general literature on consumers and health claims. Such individual related characteristics capture the individual attitude and interest in preventing health losses through food choices and diet (see for instance, Roininen et al. (1999), Van Trijp &amp; Van der Lans (2007) Dean et al. (2012)). To achieve our research goal, we employed a best-worst (BW) approach on a representative sample of Italian household members who are responsible for food shopping. Consumers tested competitively the multiple product attributes of EVOO. The share of consumers interested in health claims was detected by a latent class clustering model and characterized based on their socio-demographic, attitudinal, and psychographic features. Thus, this is the first study attempting to identify the features of consumers interested in health claims while purchasing EVOO using a large sample of household responsible of food purchases
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