474 research outputs found
Out of sight out of mind: Perceived physical distance between the observer and someone in pain shapes observer's neural empathic reactions
Social and affective relations may shape empathy to others' affective states. Previous studies also revealed that people tend to form very different mental representations of stimuli on the basis of their physical distance. In this regard, embodied cognition and embodied simulation propose that different physical distances between individuals activate different interpersonal processing modes, such that close physical distance tends to activate the interpersonal processing mode typical of socially and affectively close relationships. In Experiment 1, two groups of participants were administered a pain decision task involving upright and inverted face stimuli painfully or neutrally stimulated, and we monitored their neural empathic reactions by means of event-related potentials (ERPs) technique. Crucially, participants were presented with face stimuli of one of two possible sizes in order to manipulate retinal size and perceived physical distance, roughly corresponding to the close and far portions of social distance. ERPs modulations compatible with an empathic reaction were observed only for the group exposed to face stimuli appearing to be at a close social distance from the participants. This reaction was absent in the group exposed to smaller stimuli corresponding to face stimuli observed from a far social distance. In Experiment 2, one different group of participants was engaged in a match-to-sample task involving the two-size upright face stimuli of Experiment 1 to test whether the modulation of neural empathic reaction observed in Experiment 1 could be ascribable to differences in the ability to identify faces of the two different sizes. Results suggested that face stimuli of the two sizes could be equally identifiable. In line with the Construal Level and Embodied Simulation theoretical frameworks, we conclude that perceived physical distance may shape empathy as well as social and affective distance
Drug delivery in overcoming the blood-brain barrier: role of nasal mucosal grafting
The bloodâbrain barrier (BBB) plays a fundamental role in protecting and maintaining the homeostasis of the brain. For this reason, drug delivery to the brain is much more difficult than that to other compartments of the body. In order to bypass or cross the BBB, many strategies have been developed: invasive techniques, such as temporary disruption of the BBB or direct intraventricular and intracerebral administration of the drug, as well as noninvasive techniques. Preliminary results, reported in the large number of studies on the potential strategies for brain delivery, are encouraging, but it is far too early to draw any conclusion about the actual use of these therapeutic approaches. Among the most recent, but still pioneering, approaches related to the nasal mucosa properties, the permeabilization of the BBB via nasal mucosal engrafting can offer new potential opportunities. It should be emphasized that this surgical procedure is quite invasive, but the implication for patient outcome needs to be compared to the gold standard of direct intracranial injection, and evaluated whilst keeping in mind that central nervous system diseases and lysosomal storage diseases are chronic and severely debilitating and that up to now no therapy seems to be completely successful
Multi-wavelength SPAD photoplethysmography for cardio-respiratory monitoring
There is a growing interest in photoplethysmography (PPG) for the continuous monitoring of cardio-respiratory signals by portable instrumentation aimed at the early diagnosis of cardiovascular diseases. In this context, it is conceivable that PPG sensors working at different wavelengths simultaneously can optimize the identification of apneas and the quantification of the associated heart-rate changes or other parameters that depend on the PPG shape (e.g., systematic vascular resistance and pressure), when evaluating the severity of breathing disorders during sleep and in general for health monitoring. Therefore, the objective of this work is to present a novel pulse oximeter that provides synchronous data logging related to three light wavelengths (green, red, and infrared) in transmission mode to optimize both heart rate measurements and a reliable and continuous assessment of oxygen saturation. The transmission mode is considered more robust over motion artifacts than reflection mode, but current pulse oximeters cannot employ green light in transmission mode due to the high absorbance of body tissues at this wavelength. For this reason, our device is based on a Single-Photon Avalanche Diode (SPAD) with very short deadtime (less than 1 ns) to have, at the same time, the single photon sensitivity and high-count rate that allows acquiring all the wavelengths of interest on the same site and in transmission mode. Previous studies have shown that SPAD cameras can be used for measuring the heart rate through remote PPG, but oxygen saturation and heart-rate measures through contact SPAD-based PPG sensors have never been addressed so far. The results of the preliminary validation on six healthy volunteers reflect the expected physiological phenomena, providing rms errors in the Inter Beat Interval estimation smaller than 70 ms (with green light) and a maximum error in the oxygen saturation smaller than 1% during the apneas. Our prototype demonstrates the reliability of SPAD-based devices for continuous long-term monitoring of cardio-respiratory variables as an alternative to photodiodes especially when minimal area and optical power are required
Les paysages viticoles des Alpes occidentales = I paesaggi viticoli delle Alpi occidentali
Panoramica di confronto su paesaggi e dati della viticoltura alpina (superficie vitata, struttura fondiaria, forme di allevamento, produzione, denominazioni) nei territori di CittĂ metropolitana di Torino, Valle dâAosta, Savoia e Alta Savoia
CARATTERIZZAZIONE ACUSTICA DI NANOBOLLE LIPIDICHE
Vengono riportate misure riguardo lâefficienza di scattering di nanobolle lipidiche con diametro medio di 200 nm contenenti tetradecafluoroesano; le misure, effettuate con la tecnica pulse-echo, rivelano unâattenuazione dipendente dalla concentrazione in soluzione delle nanobolle con valori che, per una concentrazione del 35% di nanobolle in hepes, raggiungono, a 14 MHz, il valore di circa 6 dB/cm. Tale valore Ăš confrontabile
con le attenuazioni prodotte da agenti di contrasto commercialmente disponibili come, ad esempio, il SonoVueÂź.
Ă stata inoltre utilizzata una tecnica fotoacustica per la valutazione dellâefficacia di intrappolamento del gas allâinterno delle nanobolle, riscontrando, anche in questo caso, valori simili a quelli misurati nel SonoVueÂź
Duplication of the posterior cerebral artery: two case reports
The anatomy of the brain circulation is complex and variable.Autopsy studies and imaging techniques have detected
anatomical variations of cerebral arteries (CAs) in 48â58% of the general population [1]. The duplication of the posterior
cerebral artery (PCA) is a rare anatomic variant with a frequency of 2.3% [2, 3]. PCA duplication is characterised
by the identification of a âtrue foetalâ PCA, that originates from the internal carotid artery (ICA) and gives rise to the
parieto-occipital artery, the internal occipital artery, the calcarine artery and the posterior pericallosal artery, associated
with a PCA, that regularly arises from the basilar artery and gives rise to the posterior temporal artery [4]
Chitosan Glutamate-Coated Niosomes: a proposal for Nose-to-Brain delivery
The aim of this in vitro study is to prepare and characterize drug free and pentamidine loaded chitosan glutamate coated niosomes for intranasal drug delivery to reach the brain through intranasal delivery. Mucoadhesive properties and stability testing in various environments were evaluated to examine the potential of these formulations to be effective drug delivery vehicles for intranasal delivery to the brain. Samples were prepared using thin film hydration method. Changes in size and ζ-potential of coated and uncoated niosomes with and without loading of pentamidine in various conditions were assessed by dynamic light scattering (DLS), while size and morphology were also studied by atomic force microscopy (AFM). Bilayer properties and mucoadhesive behavior were investigated by fluorescence studies and DLS analyses, respectively. Changes in vesicle size and ζ-potential values were shown after addition of chitosan glutamate to niosomes, and when in contact with mucin solution. In particular, interactions with mucin were observed in both drug free and pentamidine loaded niosomes regardless of the presence of the coating. The characteristics of the proposed systems, such as pentamidine entrapment and mucin interaction, show promising results to deliver pentamidine or other possible drugs to the brain via nasal administration
Neem oil nanoemulsions: characterisation and antioxidant activity
The aim of the present work is to develop nanoemulsions (NEs), nanosized emulsions, manufactured for
improving the delivery of active pharmaceutical ingredients. In particular, nanoemulsions composed of
Neem seed oil, contain rich bioactive components, and Tween 20 as nonionic surfactant were prepared.
A mean droplet size ranging from 10 to 100nm was obtained by modulating the oil/surfactant ratio.
Physicochemical characterisation was carried out evaluating size, f-potential, microviscosity, polarity and
turbidity of the external shell and morphology, along with stability in simulated cerebrospinal fluid (CSF),
activity of Neem oil alone and in NEs, HEp-2 cell interaction and cytotoxicity studies. This study confirms
the formation of NEs by Tween 20 and Neem oil at different weight ratios with small and homogenous
dimensions. The antioxidant activity of Neem oil alone and in NEs was comparable, whereas its cytotoxicity
was strongly reduced when loaded in NEs after interaction with HEp-2 cells
Locating clustered seismicity using Distance Geometry Solvers: applications for sparse and single-borehole DAS networks
The determination of seismic event locations with sparse networks or
single-borehole systems remains a significant challenge in observational
seismology. Leveraging the advantages of the location approach HADES, which was
initially developed for locating clustered seismicity recorded at two stations,
we present here an improved version of the methodology: HADES-R. Where HADES
previously needed a minimum of 4 absolutely located master events, HADES-R
solves a least-squares problem to find the relative inter-event distances in
the cluster, and uses only a single master event to find the locations of all
events, and subsequently applies rotational optimiser to find the cluster
orientation. It can leverage iterative station combinations if multiple
receivers are available, to describe the cluster shape and orientation
uncertainty with a bootstrap approach. The improved method requires P- and
S-phase arrival picks, a homogeneous velocity model, a single master event with
a known location, and an estimate of the cluster width. The approach is
benchmarked on the 2019 Ridgecrest sequence recorded at two stations, and
applied to two seismic clusters at the FORGE geothermal test site, including a
microseismic monitoring scenario with a DAS in a vertical borehole. Traditional
procedures struggle in these settings due to the ill-posed network
configuration. The azimuthal ambiguity in this scenario is partially overcome
by assuming that all events belong to the same cluster around the master event
and a cluster width estimate. We find the cluster shape in both cases, although
the orientation remains uncertain. The method's ability to constrain the
cluster shape and location with only one well-located event offers promising
implications, especially for environments where limited or specialised
instrumentation is in use.Comment: 33 pages, 15 figures. Manuscript submitted to Geophysical Journal
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