184 research outputs found
Cosmic Ray Muons as Penetrating Probes to Explore the World around Us
Secondary cosmic muons provide a powerful probe to explore various aspects of the world around us. Various physical processes have been employed over the last years for such applications. Muon absorption was used to probe the interior of natural and man-made structures, from the Egypt pyramids to big volcanoes, contributing to interdisciplinary studies. Multiple scattering was employed to reconstruct the location of scattering centres, producing 2D and 3D images of the interior of hidden volumes (muon tomography). Additional possibilities of cosmic muons have been exploited even for the alignment of large civil structures and in the study of their stability. All these applications benefit from the development of advanced detection techniques and improvement in software algorithms. This contribution surveys the state of the art of these applications, with special emphasis on their possibilities and limitations
Real-Time Particle Radiography by Means of Scintillating Fibers Tracker and Residual Range Detectors
In this chapter, a detailed description of the construction and the procedure for the measurement of performances of a charged particle imaging system is given. Such a system can be realized by the combined use of a position sensitive detector and a residual range detector. The position sensitive detector is made up of two superimposed and right-angled planes, each of which subsists of two layers of pre-aligned and juxtaposed scintillating fibers. The selected 500 μm square section fibers are optically coupled to two silicon photomultiplier arrays adopting a channel reduction system patented by the Istituto Nazionale di Fisica Nucleare. The residual range detector consists of 60 parallel layers of the same fibers used in the position detector, each of which is optically coupled to a channel of silicon photomultiplier array by means of two wavelength-shifting fibers. The sensitive area of both detectors is 90 × 90 mm2. The performance of the prototypes was tested in different facilities with protons and carbon ions at energy up to about 250 MeV and rate up to about 109 particles per second. The comparison between simulations and measurements confirms the validity of this system. Based on the results, a future development is a real-time radiography system exploiting high-intensity pencil beams and real-time treatment plan verification
Intra- and inter-operator reliability assessment of a novel extramedullary accelerometer-based smart cutting guide for total knee arthroplasty: an in vivo study
Purpose The purpose is to verify the intra- and inter-operator reliability of an extramedullary (EM) accelerometer-based smart cutting guide for distal femoral resection during primary total knee arthroplasty (TKA). The hypothesis of the present study was that the use of the device would result in a good correlation between different operators with a difference between repeated measurements of less than 1 degrees.Methods Twenty-five not consecutive patients with knee osteoarthritis undergone to primary TKA using an EM inertial-based cutting guide to perform distal femoral resection. In order to assess the agreement in femoral axis definition of the device, two operators performed three time each the manoeuvres necessary to define axis. Inter-rater agreement was evaluated with Bland and Altman agreement test. Intra-rater repeatability was evaluated analysing average results distribution of repeated measurements. Accuracy of the device was evaluated comparing differences between intra-operative device data with final implant alignment measured on post-operative longstanding x-rays using Students' t test.Results Agreement between the two operators was statistically significant (p < 0.05) with a bias of - 0.4 degrees (95% CI -0.6 degrees to - 0.2 degrees). Average difference between cut orientation measured with device and final implant position, measured on x-rays, was 0.2 degrees (95% CI - 1.5 degrees to 1.7 degrees) with no statistical difference between the two measurements. Final implant alignment, measured on x-ray, was 90.2 degrees, with 95% of cases distributed within range 88.0 degrees to 92.0 degrees for varus-valgus and 2.8 degrees and with 95% of cases distributed within range 2.0 degrees to 4.0 degrees for flexion-extension.Conclusions The EM accelerometer-based smart cutting guide used to perform distal femoral resection during primary TKA demonstrated a good intra- and inter-operator reliability in the present in vivo study
Smart textile for respiratory monitoring and thoraco-abdominal motion pattern evaluation
The use of wearable systems for monitoring vital parameters has gained wide popularity in several medical fields. The focus of the present study is the experimental assessment of a smart textile based on 12 fiber Bragg grating sensors for breathing monitoring and thoraco‐abdominal motion pattern analysis. The feasibility of the smart textile for monitoring several temporal respiratory parameters (ie, breath‐by‐breath respiratory period, breathing frequency, duration of inspiratory and expiratory phases), volume variations of the whole chest wall and of its compartments is performed on 8 healthy male volunteers. Values gathered by the textile are compared to the data obtained by a motion analysis system, used as the reference instrument. Good agreement between the 2 systems on both respiratory period (bias of 0.01 seconds), breathing frequency (bias of −0.02 breaths/min) and tidal volume (bias of 0.09 L) values is demonstrated. Smart textile shows good performance in the monitoring of thoraco‐abdominal pattern and its variation, as well
The detection of anti-Trichinella antibodies in free-ranging Nebrodi Regional Park black pigs from Sicily, Italy, suggests the circulation of Trichinella britovi in the island
Abstract • Zoonotic nematodes of the genus Trichinella are known to occur in countries bordering the Mediterranean Sea. For example, Trichinella spiralis was reported in pigs and humans at the turn of the Second World War in Sicily and Trichinella britovi in pigs, red foxes and dogs from Corsica and Sardinia since 2004. Following the discovery of T. britovi in Corsica and Sardinia, a question arose as to whether this species was also present in Sicily which is located only 3.14 km from continental Italy. To address this query, we investigated the presence of anti-Trichinella antibodies in the serum of Nebrodi black pigs, a breed that is bred in the wild in the Nebrodi Regional Park, a protected area of the island rich in flora and fauna. Blood samples were collected from 112 Nebrodi black pigs from five farms. Sera were tested by ELISA and ELISA positive sera were confirmed by Western blot (Wb) using excretory/secretory antigens. Eighteen (16.1%) serum samples belonging to 17 fattening pigs and 1 boar tested positive by Wb. Positive sera tested by Wb using crude worm extract antigens (CWE), displayed a banding pattern similar to the CWE-Wb pattern of T. spiralis and T. britovi reference pig sera but different to that of T. pseudospiralis reference pig sera. No larvae were detected in muscles of serologically positive pigs by artificial digestion. The presence of anti-Trichinella antibodies in the absence of larvae in the muscles, suggests that the pigs were infected with T. britovi and not T. spiralis whose larvae survive in the muscles for at least two years. These results suggest that T. britovi is circulating in Nebrodi Regional Park in Sicily. ELISA testing may constitute a suitable tool for large-scale screening of Trichinella spp. infection in free-ranging pigs, when ELISA-positive sera are confirmed by Wb. Free-ranging animals can act as sentinels for the presence of zoonotic nematodes of the genus Trichinella in wildlife
Atmospheric muography for imaging and monitoring tropic cyclones
Large-scale solid bodies on Earth such as volcanoes and man-made pyramids have been visualized with solid earth muography, and the recently invented technique, acqueous muography, has already demonstrated its capability to visualize ocean tides and tsunami. In this work, atmospheric muography, a technique to visualize and monitor the vertical profile of tropic cyclones (TCs) is presented for the first time. The density distribution and time-dependent behavior of several TCs which had approached Kagoshima, Japan, has been investigated with muography. The resultant time-sequential images captured their warm cores, and their movements were consistent with the TC trails and barometric pressure variations observed at meteorological stations. By combining multidirectional muographic images with barometric data, we anticipate that muography will become a useful tool to monitor the three-dimensional density distribution of a targeted mesoscale convective system
INVESTIGATING THE SEISMIC RESPONSE OF URM WALLS WITH IRREGULAR OPENING LAYOUT THROUGH DIFFERENT MODELING APPROACHES
The façade and internal walls of unreinforced masonry (URM) buildings often present an irregular opening layout, due to architectural reasons or modifications to the structure, which make the expected seismic damage pattern less predictable a priori. Therefore, the discretization of the walls in structural components is not standardized, conversely to cases with a regular opening layout for which the available modeling methods are corroborated by seismic damage surveys reporting recurrent failure patterns. The structural component discretization is a relevant step for the code-conforming seismic assessment, typically based on comparing the internal forces and drifts of each component to strength criteria and drift thresholds. Therefore, the lack of well-established approaches can significantly influence the assessment. The issue is even more evident when the structural components must be identified a priori in the modeling stage, namely for equivalent frame models. The applicability of available methods for discretization of URM walls with irregular opening layout has been already investigated in literature, but a conclusive judgment requires further studies. In this context, this paper presents an overview of the preliminary results addressing the numerical modeling of this type of walls within the framework of the DPC-ReLUIS 2022-2024 project (Subtask 10.3), funded by the Italian Department of Civil Protection. The Subtask aims to propose consensus-based recommendations for researchers and practitioners which can contribute to harmonize the use of different modeling approaches. Seven research groups are involved in the research, adopting different modeling approaches and computer codes, but similar assumptions and the same analysis method (pushover) are used. The benchmark URM structure illustrated in the paper is a two-story wall from which four configurations with increasing irregularity of opening layout were derived. The results of four modeling approached are presented. Three of them reproduce the mechanical response of masonry at the material scale by means of FE models implemented in OpenSees, DIANA and Abaqus software, while the remaining approach describes the mechanical response of masonry at the macro-element scale in 3DMacro software. Results were compared in terms of capacity curves, predicted failure mechanisms and evolution of internal forces in piers. The adoption of consistent assumptions among the different approaches led to an overall agreement of predictions at both wall and pier scales, particularly in terms of damage pattern with higher concentration of damage at the ground story. Despite that, differences on the pushover curves have been highlighted. They are mainly due to some deviations of the internal forces in squat piers deriving from a complex load flow in these elements
NKp46-expressing human gut-resident intraepithelial V\u3b41 T cell subpopulation exhibits high anti-tumor activity against colorectal cancer
\u3b3\u3b4 T cells account for a large fraction of human intestinal intraepithelial lymphocytes (IELs) endowed with potent anti-tumor activities. However, little is known about their origin, phenotype and clinical relevance in colorectal cancer (CRC). To determine \u3b3\u3b4 IEL gut-specificity, homing and functions, \u3b3\u3b4 T cells were purified from human healthy blood, lymph nodes, liver, skin, intestine either disease-free or affected by CRC or generated from thymic precursors. The constitutive expression of NKp46 specifically identifies a new subset of cytotoxic V\u3b41 T cells representing the largest fraction of gut-resident IELs. The ontogeny and gut-tropism of NKp46pos/V\u3b41 IELs depends both on distinctive features of V\u3b41 thymic precursors and gut-environmental factors. Either the constitutive presence of NKp46 on tissue-resident V\u3b41 intestinal IELs or its induced-expression on IL-2/IL-15 activated V\u3b41 thymocytes are associated with anti-tumor functions. Higher frequencies of NKp46pos/V\u3b41 IELs in tumor-free specimens from CRC patients correlate with a lower risk of developing metastatic III/IV disease stages. Additionally, our in vitro settings reproducing CRC tumor-microenvironment inhibited the expansion of NKp46pos/V\u3b41 cells from activated thymic precursors. These results parallel the very low frequencies of NKp46pos/V\u3b41 IELs able to infiltrate CRC, thus providing new insights to either follow-up cancer progression or develop novel adoptive cellular therapies
Investigating the seismic response of URM walls with irregular opening layout through different modeling approaches
TThe façade and internal walls of unreinforced masonry (URM) buildings often present an
irregular opening layout, due to architectural reasons or modifications to the structure, which
make the expected seismic damage pattern less predictable a priori. Therefore, the
discretization of the walls in structural components is not standardized, conversely to cases
with a regular opening layout for which the available modeling methods are corroborated by
seismic damage surveys reporting recurrent failure patterns. The structural component
discretization is a relevant step for the code-conforming seismic assessment, typically based
on comparing the internal forces and drifts of each component to strength criteria and drift
thresholds. Therefore, the lack of well-established approaches can significantly influence the
assessment. The issue is even more evident when the structural components must be identified
a priori in the modeling stage, namely for equivalent frame models. The applicability of
available methods for discretization of URM walls with irregular opening layout has been
already investigated in literature, but a conclusive judgment requires further studies.
In this context, this paper presents an overview of the preliminary results addressing the
numerical modeling of this type of walls within the framework of the DPC-ReLUIS 2022-2024
project (Subtask 10.3), funded by the Italian Department of Civil Protection. The Subtask
aims to propose consensus-based recommendations for researchers and practitioners which
can contribute to harmonize the use of different modeling approaches. Seven research groups
are involved in the research, adopting different modeling approaches and computer codes,
but similar assumptions and the same analysis method (pushover) are used. The benchmark
URM structure illustrated in the paper is a two-story wall from which four configurations
with increasing irregularity of opening layout were derived. The results of four modeling
approached are presented. Three of them reproduce the mechanical response of masonry at
the material scale by means of FE models implemented in OpenSees, DIANA and Abaqus
software, while the remaining approach describes the mechanical response of masonry at the
macro-element scale in 3DMacro software. Results were compared in terms of capacity
curves, predicted failure mechanisms and evolution of internal forces in piers. The adoption
of consistent assumptions among the different approaches led to an overall agreement of
predictions at both wall and pier scales, particularly in terms of damage pattern with higher
concentration of damage at the ground story. Despite that, differences on the pushover curves
have been highlighted. They are mainly due to some deviations of the internal forces in squat
piers deriving from a complex load flow in these elements.DPC - Dipartimento della Protezione Civile, Presidenza del Consiglio dei Ministri(LA/P/0112/2020
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