382 research outputs found

    An exploratory fNIRS study with immersive virtual reality: a new method for technical implementation

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    For over two decades Virtual Reality (VR) has been used as a useful tool in several fields, from medical and psychological treatments, to industrial and military applications. Only in recent years researchers have begun to study the neural correlates that subtend VR experiences. Even if the functional Magnetic Resonance Imaging (fMRI) is the most common and used technique, it suffers several limitations and problems. Here we present a methodology that involves the use of a new and growing brain imaging technique, functional Near-infrared Spectroscopy (fNIRS), while participants experience immersive VR. In order to allow a proper fNIRS probe application, a custom-made VR helmet was created. To test the adapted helmet, a virtual version of the line bisection task was used. Participants could bisect the lines in a virtual peripersonal or extrapersonal space, through the manipulation of a Nintendo Wiimote ® controller in order for the participants to move a virtual laser pointer. Although no neural correlates of the dissociation between peripersonal and extrapersonal space were found, a significant hemodynamic activity with respect to the baseline was present in the right parietal and occipital areas. Both advantages and disadvantages of the presented methodology are discussed

    Phthalates and heavy metals as endocrine disruptors in food: A study on pre-packed coffee products

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    Phthalate plasticizers and heavy metals are widely recognized to be pollutants that interfere with key developmental processes such as masculinization. We investigated the release of phthalates and heavy metals in coffee brewed from coffee packed in single-serve coffee containers made from different types of materials: metal, biodegradable and plastics. We detected with GC\u2013MS small amounts phthalates, below the tolerated daily risks levels, in all the coffees prepared from the different types of capsules. Specifically, Di (2-ethyl-hexyl)-phthalate and DiBP: Diisobuthyl-pthalate were ubiquitously present despite the high variability among the samples (respective range 0.16\u20131.87 \u3bcg/mL and 0.01\u20130.36 \u3bcg/mL). Whereas, diethyl-phthalate (range 0.20\u20130.26 \u3bcg/mL) and di-n-buthyl-phthalate (range 0.02\u20130.14 \u3bcg/mL) were detected respectively in one and three out of the four types of capsule tested. In contrast, we detected by atomic mass spectrometry on mineralized samples heavy metals lead (Pb) and nickel (Ni), in all coffee tested. PB levels (respective range 0.32\u2013211.57 \u3bcg/dose) accounted for 42\u201379%, whereas Ni levels (respective range 166.25\u20131950.26 \u3bcg/dose) accounted for >100% of the tolerable daily intake. These results add to the already present concerns related to the multiple pathways of human exposure and the ubiquitous presence of these pollutants in consumer products and their long-term effect on human health

    Spray-drying Microencapsulation of an Extract from Tilia tomentosa Moench Flowers: Physicochemical Characterization and in Vitro Intestinal Activity

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    Silver linden (Tilia tomentosa Moench, TtM) flowers possess several health-promoting properties, especially at the neurological level, such as intestinal relaxation activity associated with specific flavonols, particularly quercetin and kaempferol derivatives. However, such molecules are susceptible to degradation upon different triggers like heat, light and extreme pH values. To overcome the scarce stability of TtM flowers bioactive molecules and make them suitable for developing functional food and supplements, we applied microencapsulation. Spray-drying microencapsulation of TtM flowers extract was performed using three starch-derived wall materials: maltodextrin 12 DE (MD12) and 19 DE (MD19), and OSA-modified starch (OSA-S). The stability of total phenols, flavanols, and antioxidant capacity was monitored for 70 days under accelerated stress conditions (40 °C/70% RH) by HPLC and spectrophotometric methods, and the intestinal contractile activity was tested in a murine model. In comparison to MD12 and MD19, OSA-S stood out for the higher encapsulation efficiency of quercetin and kaempferol glycosides (+ 36-47% compared to MD12 and + 18-24% compared to MD19) and stability thereof (half-life on average + 30% compared to MD12 and + 51% compared to MD19). The intestinal contractile activity of OAS-S powders resulted comparable to the original extract, indicating that flavonols were biologically active and accessible. Our results underly the potential advantages of OSA-S encapsulated formulation as a functional ingredient for the development of nutraceutical products

    Manganese(II) Molecular Sources for Plasma-Assisted CVD of Mn Oxides and Fluorides: From Precursors to Growth Process

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    A viable route to manganese-based materials of high technological interest is plasma-assisted chemical vapor deposition (PA-CVD), offering various degrees of freedom for the growth of high-purity nanostructures from suitable precursors. In this regard, fluorinated \u3b2-diketonate diamine Mn(II) complexes of general formula Mn(dik)2\ub7TMEDA [TMEDA = N,N,N\u2032,N\u2032-tetramethylethylenediamine; Hdik = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (Hhfa), or 1,1,1-trifluoro-2,4-pentanedione (Htfa)] represent a valuable option in the quest of candidate molecular sources for PA-CVD environments. In this work, we investigate and highlight the chemico-physical properties of these compounds of importance for their use in PA-CVD processes, through the use of a comprehensive experimental\u2013theoretical investigation. Preliminary PA-CVD validation shows the possibility of varying the Mn oxidation state, as well as the system chemical composition from MnF2 to MnO2, by simple modulations of the reaction atmosphere, paving the way to a successful utilization of the target compounds in the growth of manganese-containing nanomaterials for different technological applications

    Characterization of seed proanthocyanidins of thirty-two red and white hybrid grape varieties

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    Grape seed extracts are known for their beneficial effects on health and on cardiovascular diseases due to antioxidant activity and the free radical-scavenging properties of proanthocyanidins (PAs). Moreover, grape seed tannins are used in oenology as additives to improve the organoleptic characteristics of wines, and for the clarification of must and wines. PAs in seed extract of 32 hybrid and three V. vinifera grape varieties were characterized by MALDI-TOF mass spectrometry. Signals of 148 compounds were identified as [M+H]+, [M+Na]+ and [M+K]+ adducts of B-type and A-type PAs formed from catechin/epicatechin subunits up to undecamers and with galloylation degree 0-7. The number-average molecular weight (Mn) of the samples, a parameter correlated with the molecular weight of polymers, and the polyphenolic content of extract, were also determined. Profiles of the hybrid grape varieties were compared with those of three V. vinifera samples studied as references. 'Terzi 108-6' showed high content of antioxidant polyphenols and 'Seyve Villard 12-390' higher content of higher oligomers. These two grape varieties are therefore potentially very interesting as sources of antioxidants and tannins for nutraceutical and oenological uses

    Proteomics goes forensic: detection and mapping of blood signatures in fingermarks

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    A bottom up in situ proteomic method has been developed enabling the mapping of multiple blood signatures on the intact ridges of blood fingermarks byMatrix Assisted Laser Desorption Mass Spectrometry Imaging (MALDI-MSI). This method, at a proof of concept stage, builds upon recently published work demonstrating the opportunity to profile and identify multiple blood signatures in bloodstains via a bottom up proteomic approach. The present protocol addresses the limitation of the previously developed profiling method with respect to destructivity; destructivity should be avoided for evidence such as blood fingermarks, where the ridge detail must be preserved in order to provide the associative link between the biometric information and the events of bloodshed. Using a blood mark reference model, trypsin concentration and spraying conditions have been optimised within the technical constraints of the depositor eventually employed; the application of MALDI-MSI and Ion Mobility MS have enabled the detection, confirmation and visualisation of blood signatures directly onto the ridge pattern. These results are to be considered a first insight into a method eventually informing investigations (and judicial debates) of violent crimes in which the reliable and non-destructive detection and mapping of blood in fingermarks is paramount to reconstruct the events of bloodshed

    Action ability modulates time‑to‑collision judgments

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    Time-to-collision (TTC) underestimation has been interpreted as an adaptive response that allows observers to have more time to engage in a defensive behaviour. This bias seems, therefore, strongly linked to action preparation. There is evidence that the observer’s physical fitness modulates the underestimation effect so that people who need more time to react (i.e. those with less physical fitness) show a stronger underestimation effect. Here we investigated whether this bias is influenced by the momentary action capability of the observers. In the first experiment, participants estimated the time-to-collision of threatening or non-threatening stimuli while being mildly immobilized (with a chin rest) or while standing freely. Having reduced the possibility of movement led participants to show more underestimation of the approaching stimuli. However, this effect was not stronger for threatening relative to non-threatening stimuli. The effect of the action capability found in the first experiment could be interpreted as an expansion of peripersonal space (PPS). In the second experiment, we thus investigated the generality of this effect using an established paradigm to measure the size of peripersonal space. Participants bisected lines from different distances while in the chin rest or standing freely. The results replicated the classic left-to-right gradient in lateral spatial attention with increasing viewing distance, but no effect of immobilization was found. The manipulation of the momentary action capability of the observers influenced the participants’ performance in the TTC task but not in the line bisection task. These results are discussed in relation to the different functions of PPS
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