46 research outputs found
Aerosol Synthesis of N and N-S Doped and Crumpled Graphene Nanostructures
Chemically modified graphene-based materials (CMG) are currently attracting a vast interest in their application in different fields. In particular, heteroatom-doped graphenes have revealed great potentialities in the field of electrocatalysis as substitutes of fuel cell noble metal-based catalysts. In this work, we investigate an innovative process for doping graphene nanostructures. We optimize a novel synthetic route based on aerosol preparation, which allows the simultaneous doping, crumpling, and reduction of graphene oxide (GO). Starting from aqueous solutions containing GO and the dopant precursors, we synthesize N-and N,S-dual-doped 3D graphene nanostructures (N-cGO and N,S-cGO). In the aerosol process, every aerosol droplet can be considered as a microreactor where dopant precursors undergo thermal decomposition and react with the GO flakes. Simultaneously, thanks to the relatively high temperature, GO undergoes crumpling and partial reduction. Using a combination of spectroscopic and microscopic characterization techniques, we investigate the morphology of the obtained materials and the chemical nature of the dopants within the crumpled graphene sheets. This study highlights the versatility of the aerosol process for the design of new CMG materials with tailored electrocatalytic properties.</p
Partial Discharges detection in 1 MV power supplies in MITICA experiment, the ITER Heating Neutral Beam Injector prototype
MITICA (Megavolt ITER Injector & Concept Advancement), the full scale
prototype of ITER Heating Neutral Beam, is under realization at the Neutral
Beam Test Facility (Padova, Italy). It is designed to deliver 16.5 MW to ITER
plasma, obtained by accelerating negative Deuterium ions up to 1 MeV for a
total ion current of 40 A and then neutralized. MITICA Acceleration Power
Supply is composed of several non-standard equipment, beyond industrial
standard for insulation voltage level (-1 MVdc) and dimensions. Voltage
withstand tests (up to 1.265 MVdc) have been performed in five subsequent steps
(from 2018 to 2019), according to the installation progress, after connecting
equipment belonging to different procurements. During integrated commissioning,
started in 2021, two breakdowns occurred in a position of the HV plant not
still identified, so they could be occurred either in air or in SF6. To
identify the locations of possible weak insulation points, the existing
diagnostics for partial discharge detection (the precursor of breakdowns) as a
first step have been improved on air-insulated parts by consisting in a set of
instrumentation, like capacitive probes and off-the-shelf instruments for AC
application (acoustic and electromagnetic sensors). The paper deals with the
instruments qualification to assess their suitability for DC usage and then
with the investigation performed in MITICA, in particular: 1) sensitivity
assessment campaign, with artificially produced corona effect to identify the
minimum threshold of each diagnostics 2) voltage application to MITICA plant,
moving the instrumentation around equipment and increasing progressively the
voltage looking for corona phenomena to identify possible weak insulation
points.Comment: Nine pages, twelve figures, accepted manuscript of a paper published
in Fusion Engineering and Desig
Customized bioreactor enables the production of 3D diaphragmatic constructs influencing matrix remodeling and fibroblast overgrowth
The production of skeletal muscle constructs useful for replacing large defects in vivo, such as in congenital diaphragmatic hernia (CDH), is still considered a challenge. The standard application of prosthetic material presents major limitations, such as hernia recurrences in a remarkable number of CDH patients. With this work, we developed a tissue engineering approach based on decellularized diaphragmatic muscle and human cells for the in vitro generation of diaphragmatic-like tissues as a proof-of-concept of a new option for the surgical treatment of large diaphragm defects. A customized bioreactor for diaphragmatic muscle was designed to control mechanical stimulation and promote radial stretching during the construct engineering. In vitro tests demonstrated that both ECM remodeling and fibroblast overgrowth were positively influenced by the bioreactor culture. Mechanically stimulated constructs also increased tissue maturation, with the formation of new oriented and aligned muscle fibers. Moreover, after in vivo orthotopic implantation in a surgical CDH mouse model, mechanically stimulated muscles maintained the presence of human cells within myofibers and hernia recurrence did not occur, suggesting the value of this approach for treating diaphragm defects
Lifestyles and socio-cultural factors among children aged 6-8 years from five Italian towns: The MAPEC-LIFE study cohort
Background: Lifestyles profoundly determine the quality of an individual’s health and life since his childhood.
Many diseases in adulthood are avoidable if health-risk behaviors are identified and improved at an early stage of
life. The aim of the present research was to characterize a cohort of children aged 6–8 years selected in order to
perform an epidemiological molecular study (the MAPEC_LIFE study), investigate lifestyles of the children that
could have effect on their health status, and assess possible association between lifestyles and socio-cultural factors.
Methods: A questionnaire composed of 148 questions was administered in two different seasons to parents of
children attending 18 primary schools in five Italian cities (Torino, Brescia, Pisa, Perugia and Lecce) to obtain
information regarding the criteria for exclusion from the study, demographic, anthropometric and health
information on the children, as well as some aspects on their lifestyles and parental characteristics. The results
were analyzed in order to assess the frequency of specific conditions among the different seasons and cities and
the association between lifestyles and socio-economic factors.
Results: The final cohort was composed of 1,164 children (50.9 boys, 95.4% born in Italy). Frequency of some
factors appeared different in terms of the survey season (physical activity in the open air, the ways of cooking
certain foods) and among the various cities (parents’ level of education and rate of employment, sport, traffic
near the home, type of heating, exposure to passive smoking, ways of cooking certain foods). Exposure to
passive smoking and cooking fumes, obesity, residence in areas with heavy traffic, frequency of outdoor play and
consumption of barbecued and fried foods were higher among children living in families with low educational
and/or occupational level while children doing sports and consuming toasted bread were more frequent in families
with high socio-economic level.
Conclusions: The socio-economic level seems to affect the lifestyles of children enrolled in the study including
those that could cause health effects. Many factors are linked to the geographical area and may depend on
environmental, cultural and social aspects of the city of residence
The rapid spread of SARS-COV-2 Omicron variant in Italy reflected early through wastewater surveillance
The SARS-CoV-2 Omicron variant emerged in South Africa in November 2021, and has later been identified worldwide,
raising serious concerns.
A real-time RT-PCR assay was designed for the rapid screening of the Omicron variant, targeting characteristic mutations
of the spike gene. The assay was used to test 737 sewage samples collected throughout Italy (19/21 Regions) between
11 November and 25 December 2021, with the aim of assessing the spread of the Omicron variant in the
country. Positive samples were also tested with a real-time RT-PCR developed by the European Commission, Joint
Research Centre (JRC), and through nested RT-PCR followed by Sanger sequencing.
Overall, 115 samples tested positive for Omicron SARS-CoV-2 variant. The first occurrence was detected on 7
December, in Veneto, North Italy. Later on, the variant spread extremely fast in three weeks, with prevalence of positive
wastewater samples rising from 1.0% (1/104 samples) in the week 5–11 December, to 17.5% (25/143 samples)
in the week 12–18, to 65.9% (89/135 samples) in the week 19–25, in line with the increase in cases of infection with
the Omicron variant observed during December in Italy. Similarly, the number of Regions/Autonomous Provinces in
which the variant was detected increased fromone in the first week, to 11 in the second, and to 17 in the last one. The
presence of the Omicron variant was confirmed by the JRC real-time RT-PCR in 79.1% (91/115) of the positive samples,
and by Sanger sequencing in 66% (64/97) of PCR amplicons
The rapid spread of SARS-COV-2 Omicron variant in Italy reflected early through wastewater surveillance
The SARS-CoV-2 Omicron variant emerged in South Africa in November 2021, and has later been identified worldwide, raising serious concerns. A real-time RT-PCR assay was designed for the rapid screening of the Omicron variant, targeting characteristic mutations of the spike gene. The assay was used to test 737 sewage samples collected throughout Italy (19/21 Regions) between 11 November and 25 December 2021, with the aim of assessing the spread of the Omicron variant in the country. Positive samples were also tested with a real-time RT-PCR developed by the European Commission, Joint Research Centre (JRC), and through nested RT-PCR followed by Sanger sequencing. Overall, 115 samples tested positive for Omicron SARS-CoV-2 variant. The first occurrence was detected on 7 December, in Veneto, North Italy. Later on, the variant spread extremely fast in three weeks, with prevalence of positive wastewater samples rising from 1.0% (1/104 samples) in the week 5-11 December, to 17.5% (25/143 samples) in the week 12-18, to 65.9% (89/135 samples) in the week 19-25, in line with the increase in cases of infection with the Omicron variant observed during December in Italy. Similarly, the number of Regions/Autonomous Provinces in which the variant was detected increased from one in the first week, to 11 in the second, and to 17 in the last one. The presence of the Omicron variant was confirmed by the JRC real-time RT-PCR in 79.1% (91/115) of the positive samples, and by Sanger sequencing in 66% (64/97) of PCR amplicons. In conclusion, we designed an RT-qPCR assay capable to detect the Omicron variant, which can be successfully used for the purpose of wastewater-based epidemiology. We also described the history of the introduction and diffusion of the Omicron variant in the Italian population and territory, confirming the effectiveness of sewage monitoring as a powerful surveillance tool
The Micro-Vasculature of the Cochlea: Studies in Animal Models of Sensorineural Hearing Loss
This thesis concerns the role of cochlear microvasculature in normal hearing function and in pathological conditions that result in hearing loss. In animal models we have investigated two major types of sensorineural hearing loss where degeneration of the stria vascularis has been implicated, namely presbyacusis and hearing loss associated with cytomegalovirus (CMV) infection. The former eventual affects all aging humans; the latter is a common etiology for congenital hearing loss in infants.
The focus of experimental work is on the capillary networks of the cochlea. We chose to use corrosion cast techniques to visualize and quantify capillary vessel parameters. For the small and delicate cochleas of our mouse models, this required extensive technical improvements to corrosion casting methodology. These innovations proved successful.
Three experimental animal model studies were made. The first involved analysis, and modeling of strial feeding arterioles in normal subject. The hypothesis posed was that the highly convoluted structure of these vessels acts to dampen cardiovascular pulsations within the cochlea and thereby prevent self-stimulation by such biological noise. The results from this study support the hypothesis.
In our murine models of presbyacusis and of CMV infection we correlated loss of auditory thresholds measured with ABR methods, with degenerative changes to cochlear microvasculature. In mice with age-related, high frequency hearing loss, we report significant vascular degeneration of stria vascularis in basal (high frequency) cochlear areas compared to more apical regions.
After CMV infection in newborn mice, we observed at 6 weeks a wide range of auditory threshold changes. At 8 weeks post-infection, the cochleas had suffered a wide range of vascular damage. The most vulnerable structure was stria vascularis in the mid-apical cochlear turn. Our novel finding that vascular damage is the primary lesion after CMV infection is consistent with some clinical characteristics of this hearing loss type in infants.Ph.D