BACKGROUND This study was designed to establish the number and area (as a percentage) of bronchial wall vessels in subjects with and without asthma, to obtain information on the morphology of the ...vessels, and to see whether changes differed in patients with mild, moderate, and severe asthma. METHODS Biopsy specimens were taken using a rigid bronchoscope from the carina of the middle lobe bronchus of 20 patients with allergic asthma and 20 non-asthmatic controls. Specimens were sectioned and stained with haematoxylin-eosin, Masson trichrome, PAS, alcian blue-PAS, and orcein. The vessels were counted and the vascular area was calculated as a percentage in the lamina propria, in blind conditions, on PAS stained sections in 50 microscopic fields (magnification ×1000, 0.02 mm2 per field). The vascular area was calculated using the points counting procedure (Chalkley point array). The vascular morphology, intravascular cells, and the perivascular area were also studied using a magnification up to ×1200. RESULTS Patients with asthma had more vessels (mean (SD) 226.70 (74.53)v 172.05 (30.58), p=0.0043) and a larger percentage vascular area (8.61 (2.38)% v6.81 (2.25)%, p=0.028) than non-asthmatic subjects. Patients with severe asthma had significantly more vessels than those with mild or moderate disease (p=0.0044). Asthmatic capillaries and venules had oedematous walls and thickening of the subendothelial basement membrane, and hypotrophic or atrophic myocytes and fibrosis in the arterioles. Vessels from asthmatic subjects showed eosinophil recruitment, activation, and intravascular lysis. Intense eosinophil recruitment was associated with more marked vascular structural changes. Muscular formations protruded into the lumen in the arterioles of both groups, and in asthmatics these had hypotrophic or atrophic myocytes and fibrosis. CONCLUSIONS Morphometric analysis showed that the bronchial lamina propria of asthmatic subjects had a larger number of vessels, occupying a larger percentage area than in non-asthmatic subjects. The number of vessels was correlated with the severity of the asthma. Marked alterations to the vascular structure appeared to be associated with intense eosinophil recruitment and intravascular activation. This is the first report of asthmatic and non-asthmatic bronchial wall specimens containing intra-arteriolar muscular formations, presumably to regulate blood flow to the capillary network and/or sinusoids. This function might be impaired when these structures are remodelled in asthmatic patients.
The paper investigates the electrical properties of the junction between the graphene oxide (GO) and some metals (Cu and Au). A simple humidity sensor, based on the adsorption of water molecules on ...the GO/surface in a GO/Cu junction, is described. The GO was drop-casted as a thin film, 10 μm in thickness, on the metallic substrate. The junction open-circuit voltage and short-circuit current behaviours versus the humidity level can be explained on the base of the charge carrier drift. The room temperature response of the GO/Cu water vapour detector, in terms of relative humidity in air, is compared against a well-known commercial hygrometer. The proposed device does not require external polarization, and it is inexpensive and easy to use.
Visual exposure to extreme-sized bodies elicits explicit self-body image variations. Several features of such modulation remain to be clarified. In this study we explored whether this effect: (i) ...acts on implicit mechanisms in modifying one’s body-size perception, (ii) is body-exposure-specific also at the implicit level, and (iii) is modulated by interoceptive sensibility. We assigned a covert attention task to 100 women, exposing them to extreme-sized bodies (thin and fat) or extreme-sized objects (thin and fat bottles). Before and after the attentional exposure, we tested the association between the “self/others” and “thin/fat” concepts using an Implicit Association Test. We also collected a measure of interoceptive sensibility by means of a self-report questionnaire. Results showed that participants exposed to fat bodies implicitly presented a stronger association between the “self” and “thin” concepts. This association was significantly weaker in the group exposed to thin bodies. This effect was absent after exposure to thin and fat bottles. Notably, participants with a higher tolerance of negative bodily interoceptive signals were less susceptible to the malleability of body image exerted by the exposure attentional task. Our findings shed new light on the relationship between the perception of internal (e.g., visceral) and external (e.g., visual) signals in the representation of our body.
Graphene-based materials have peculiar optical, electrical, mechanical and chemical properties, which make them useful for making thin films and thick sheets suitable for different needs. Matter ...physics, nuclear physics, microelectronics, biomedicine, engineering, agriculture and cultural heritage just represent some of the sectors in which these materials can be successfully used. The advancements allow us to go from a given graphene-based material to another transforming, for example, the insulator graphene oxide to electrically and thermally conductive reduced graphene oxide. Thanks to the interesting properties possessed by graphene-based materials, it is possible to realize gas sensors, dosimeters for ionizing radiation, light detectors, electronic devices, membranes for gases and desalination, biocompatible surfaces, medical protheses and thin coating films to preserve underlying layers. Different analysis techniques are presented to control the physical modifications of reduced graphene oxide (rGO) due to the different treatments for the pristine one. The paper reports the possibility to realize GO micro-dosimeters for ionizing radiations, sensors for air humidity and other gases, field effect transistors as the detector of visible and UV radiations, GO and rGO membranes realization for different gases, source ion strippers to enhance the charge state of different ions to be accelerated. Some of these aspects and possible applications will be presented and discussed with measurements carried out in our laboratories.
A compressible capacitive mechanical pressure sensor has been developed. Porous polydimethylsiloxane (p-PDMS) has been chosen as dielectric insulator because of its dielectric constant value. Gold ...nanoparticles have been embedded in p-PDMS to change the dielectric properties and to tune its elasticity. p-PDMS and its nanocomposite have been synthesized using the
sugar leaching
process. The p-PDMS physical characterization, with and without the gold nanoparticles, has been conducted to investigate its elastic response to compressive stresses as a function of both the polymer preparation thermal treatment and the gold nanoparticle concentration. A sensor operating in a low-pressure range between about 100 Pa and 10 kPa with a strain ranging between about 5% and 95% has been realized. Dielectric constant and electrical resistivity measurements have been performed using samples with a starting volume of the order of 1 cm
3
. The relationship between the dielectric constant, the electrical resistivity and the compressive stress/strain has been also deduced. The described sensor is flexible, biocompatible, water equivalent and can have applications in biomedicine (orthopedic, dentistry), engineering (stress–strain measurements, robotics), and microelectronics (microbalances, stress test on electronic devices).
Graphene nanoplatelets/polydimethylsiloxane (GNPs/PDMS) nanocomposites foils are obtained by dispersing nanoplatelets of graphene (GNPs) into polydimethylsiloxane (PDMS) at a given GNPs concentration ...but at different curing times to study the effects of curing time on some their bulk and surface properties. Their appearance and morphology have been examined by optical and scanning electron microscopies, their wettability and roughness by the sessile drop method and profilometry, their bonds by µRaman and ATR-FTIR spectroscopies, their dielectric response by dielectric spectroscopy. In particular, optical and SEM images and roughness measurements indicate a roughened and hydrophobic surface at the shortest curing time that becomes less roughened, more uniform and less hydrophobic as curing time increases. ATR-FTIR and µRaman spectra reveal the absence of chemical interaction between GNPs and PDMS. The behavior of the PDMS real and imaginary parts of dielectric permittivity without and with GNPs and at increasing curing times seems to define the obtained GNPs/PDMS nanocomposites as low-loss materials. The obtained results show that the curing time significantly affects the filler distribution in the PDMS matrix and consequently the properties of the final nanocomposites.
In this article, we report a study carried out to understand how changes in environment and temperature, in which the graphene oxide (GO) film reduction occurs, alter the electrical properties of the ...resulting films. In fact, it is possible to improve the GO reduction efficiency by choosing suitable environment and temperature. To this purpose, three different environments (high vacuum, air and nitrogen) and three dissimilar temperatures (177 °C, 300 °C and 600 °C) have been chosen, as suggested by differential scanning calorimetry (DSC) measurements. Among the investigated thermally reduced graphene oxide films, the ones treated at 600 °C in nitrogen have shown to possess higher electrical conductivity. Such an enhanced electrical conductivity can be attributed to reduction of oxygen functional groups and restoration of sp
2
carbon network, as confirmed by Raman spectra.
•The role of vestibular signals in body representation is still debated.•We measured implicit and explicit representation parameters during CVS.•Our results show that CVS decreases body temperature ...and increases tactile acuity.•We suggest a dynamic role of the vestibular system in updating the body matrix.
Homeostatic parameters, such as temperature, are related to body representation. In this study, we measured whether caloric vestibular stimulation (CVS) alters body temperature and tactile processing, and if in the direction predicted by a holistic body matrix representation.
Skin temperature and tactile two-point discrimination (TPD) acuity were measured for both arms before, immediately after and with a delay from CVS. Participants were also administered a personality questionnaire and an anxiety inventory to rule out confounding factors. Two control experiments were planned to exclude casual variations.
Our results show that temperature drops significantly in both arms after CVS. CVS also induces a bilateral improvement in tactile acuity (even though not immediately after but in the delayed condition). Finally, these effects are not due to learning, as demonstrated by the control experiment.
In summary, our results suggest that vestibular stimulation updates body representation, supporting the evidence in favor of a body matrix.
In the present study, the effects of soft X-ray irradiation on graphene oxide (GO) films are discussed. In particular, by means of the XPS technique, it has been observed that even with a short ...exposure time GO is sensitive to the soft x-ray radiation. The X-ray radiation effects were investigated evaluating the C/O atomic ratio. Different irradiation times were applied ranging between 12 and 450 min. Significant modifications were detected in the C/O ratio and consequently in the C1s and O1s XPS profiles. At the highest soft X-ray exposure times, we disclosed the transformation of the C-OH groups to the phenol/aromatic diol ones.
At present graphene is the most exciting star in the materials science but graphene oxide, GO, that is its low-cost precursor attracts researchers from various fields because it is very easily ...produced at low cost. GO is an electrical insulator than can be transformed into graphene through the 'reduction' process. The oxygen functional groups it contains can be removed by various ways, also using lasers, ion beams and the intercalation process. The intensive research on graphene has allowed the rediscovery of various graphite-like layered materials with composition other than carbon, but properties are not yet fully known and with interesting possible applications. Among them, manganese thiophosphate, MnPS
3
, is a layered inorganic host matrix for making, through the intercalation-exfoliation-restacking technique, multi-functional hybrid thin films that can find application as optical switches, transparent coatings, in catalysis and photocatalysis, as lubricants, to create new multilayer structures, as dielectric substrates for graphene-based electronics and so on. If exfoliated at few layers, MnPS
3
allows to realize good ultraviolet photodetectors with a gate tunable photoresponsivity and high photo gain. Recent progress in these graphene-like materials will be presented and discussed together with measurements based on the use of lasers, ion beams and intercalation emphasizing their potential applications.
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