649 research outputs found
Probiotics and Prebiotics in Pediatrics
The goal of this Special Issue, “Probiotics and Prebiotics in Pediatrics”, is to focus on the importance of pediatric nutrition with probiotics and prebiotics to improve gastrointestinal health in newborn, infants, and children.Specifically, the aim is to clarify if probiotics and prebiotics can influence gut microbiota composition and host-interaction favoring human health and preventing diseases.This new information will provide health care professionals with a widespread, clear and update evidence on probiotics and prebiotics and intestinal gut microbiota in pediatric care
Two-node curved inverse finite element formulations based on exact strain-displacement solution
The inverse finite element method (iFEM) is an efficient algorithm developed for real-time monitoring of structures equipped by a network of strain sensors. The inverse element for modeling curved beams was previously developed using an approximate solution based on independently interpolated displacement components. In this study, a new formulation is proposed by the development of a least-squares variational principle using the kinematic framework of the curved beam theory. The library of existing iFEM-based elements is expanded by introducing three different inverse curved elements named iCB3, iCB4 and iCB5 respectively. This new formulation has been developed considering the exact solution of the curved beam theory that corresponds to the membrane-bending coupling and the explicit statement of the rigid-body motions. The three inverse elements, which require three, four and five measurement points respectively, extend the practical utility of iFEM for shape sensing analysis of curved structures according to the minimum available quantity of strain sensors. The effectiveness and higher accuracy of the iCB/iFEM methodology compared to other solutions present in literature are demonstrated considering numerical studies on curved beams under static transverse force and distributed loading conditions. For these problems, the effect of strain measurements error, number of sensors and discretization refinement on the solution accuracy is evaluated
Automated classification of civil structures defects based on Convolutional Neural Network
Today, the most used method for civil infrastructure inspection is based on visual assessment performed by certified inspectors following prescribed protocols. However, the increase in aggressive environmental and load conditions, coupled with the achievement for many structures of the end life-cycle, highlighted the need to automate damage identification to satisfy the number of structures that need to be inspected. To overcome this challenge, the current paper presents a method to automate the concrete damage classification using a deep Convolutional Neural Network (CNN). The CNN is designed after an experimental investigation among a wide number of pretrained networks, all applying the transfer learning technique. Training and Validation are performed using a built database with 1352 images balanced between “undamaged”, “cracked”, and “delaminated” concrete surface.
To increase the network robustness compared to images with real-world situations, different
configurations of images has been collected from Internet and on-field bridge inspections.
The GoogLeNet model is selected as the most suitable network for the concrete damage
classification, having the highest validation accuracy of about 94%. The results confirm that
the proposed model can correctly classify images from real concrete surface of bridges, tunnel
and pavement, resulting an effective alternative to the current visual inspection
Non-thermal photons and H2 formation in the early Universe
The cosmological recombination of H and He at z \sim 1000 and the formation
of H2 during the dark ages produce a non-thermal photon excess in the Wien tail
of the cosmic microwave background (CMB) blackbody spectrum. Here we compute
the effect of these photons on the H- photodetachment and H2+ photodissociation
processes. We discuss the implications for the chemical evolution of the
Universe in the post-recombination epoch, emphasizing how important a detailed
account of the full vibrational manifold of H2 and H2+ in the chemical network
is. We find that the final abundances of H2, H2+, H3+ and HD are significantly
smaller than in previous calculations that neglected the effect of non-thermal
photons. The suppression is mainly caused by extra hydrogen recombination
photons and could affect the formation rate of first stars. We provide simple
analytical approximations for the relevant rate coefficients and briefly
discuss the additional effect of dark matter annihilation on the considered
reaction rates.Comment: 10 pages, 12 figures, 1 table; accepted for publication in MNRA
Mother and infant body mass index, breast milk leptin and their serum leptin values
Purpose: This study investigates correlations between mother and infant Body Mass Index (BMI), their serum leptin values and breast milk leptin concentration in early infancy. Subjects and Methods: We determined serum leptin values in 58 healthy infants and leptin values in their mothers’ breast milk, using radioimmunoassay (RIA). Infant and maternal anthropometrics were measured. Results: Median leptin concentration was 3.9 ng/mL (interquartile range (IQR): 2.75) in infant serum, 4.27 ng/mL (IQR: 5.62) in maternal serum and 0.89 ng/mL (IQR: 1.32) in breast milk. Median maternal BMI and weight were 24 kg/m2 (IQR: 4.41) and 64 kg (IQR: 15). Median infant BMI was 15.80 kg/cm2 (IQR: 4.02), while average weight was 5.130 kg (IQR: 1.627). Infants serum leptin values positively correlated with infants’ BMI (p = 0.001; r = 0.213) and breast milk leptin (p = 0.03; r = 0.285). Maternal serum leptin values positively correlated with maternal BMI (p = 0.000, r = 0.449) and breast milk leptin ones (p = 0.026; r = 0.322). Conclusion: Breast milk leptin and maternal BMI could influence infant serum leptin values. Further studies are needed to better elucidate the role of genetics and environment on infant leptin production and risk of obesity later in life
Shape-Sensing of Beam Elements Undergoing Material Nonlinearities
The use of in situ strain measurements to reconstruct the deformed shape of structures is a key technology for real-time monitoring. A particularly promising, versatile and computationally efficient method is the inverse finite element method (iFEM), which can be used to reconstruct the displacement field of beam elements, plate and shell structures from some discrete strain measurements. The iFEM does not require the knowledge of the material properties. Nevertheless, it has always been applied to structures with linear material constitutive behavior. In the present work, advances are proposed to use the method also for concrete structures in civil engineering field such as bridges normally characterized by material nonlinearities due to the behavior of both steel and
concrete. The effectiveness of iFEM, for simply supported reinforced concrete beam and continuous beams with load conditions that determine the yielding of reinforcing steel, is studied. In order to assess the influence on displacements and strains reconstructions, different measurement stations and mesh configurations are considered. Hybrid procedures employing iFEM analysis supported by bending moment-curvature relationship are proposed in case of lack of input data in plastic zones. The reliability of the results obtained is tested and commented on to highlight the effectiveness of the approach
Application of Inverse Finite Element Method to Shape Sensing of Curved Beams
Curved beam, plate, and shell finite elements are commonly used in the finite element modeling of a wide range of civil and mechanical engineering structures. In civil engineering, curved elements are used to model tunnels, arch bridges, pipelines, and domes. Such structures provide a more efficient load transfer than their straight/flat counterparts due to the additional strength provided by their curved geometry. The load transfer is characterized by the bending, shear, and membrane actions. In this paper, a higher-order curved inverse beam element is developed for the inverse Finite Element Method (iFEM), which is aimed at reconstructing the deformed structural shapes based on real-time, in situ strain measurements. The proposed two-node inverse beam element is based on the quintic-degree polynomial shape functions that interpolate the kinematic variables. The element is C2 continuous and has rapid convergence characteristics. To assess the element predictive capabilities, several circular arch structures subjected to static loading are analyzed, under the assumption of linear elasticity and isotropic material behavior. Comparisons between direct FEM and iFEM results are presented. It is demonstrated that the present inverse beam finite element is both efficient and accurate, requiring only a few element subdivisions to reconstruct an accurate displacement field of shallow and deep curved beams
Dynamic response of PC bridge beams under different damages
The present paper describes the dynamic test campaign on prestressed concrete bridge beams taken from a dismantled viaduct in Turin, Italy after a service life of 50 years in the framework of BRIDGE|50 research project. Dynamic measurements were previously performed on the decks from which the 29 beams were taken to characterize the behaviour of the viaduct in service condition. Successively the single beams are tested to analyse and evaluate the effects of the different damage levels on the dynamic properties. The vibration data have been collected before the application of static load, after the first cracking condition and after the maximum load applied on the beam to extract the principal modal components. The results highlight the correlation among the evolution of the damage and the dynamic response of the beam and then the effectiveness of vibration tests to identify the occurrence of damages and follow their evolution. The experimental findings could be used in future works to explore the effects of damages of the single beams on the global response of this bridge typology. This work presents the results of the experimental tests on the first eight beams tested
Position paper of the Italian Chapter, International Society Cardiovascular Ultrasound
SummaryBackground Over the last two decades the interest on patent foramen ovale (PFO) as a cause of cardioembolism in cryptogenic stroke has tremendously increased, thanks to the availability of better techniques to diagnose cardiac right-to-left shunt by ultrasounds and of percutaneous means of PFO treatment with interventional techniques. Many studies have been published that have attempted to define diagnostic methodology, prognosis, and optimal treatment (pharmacological or percutaneous closure) of PFO patients with cryptogenic stroke. Unfortunately, even today, definitive evidence is still lacking, and clinical management is not consistent among cardiologists. Aims This review aims to evaluate the role of PFO in cryptogenic stroke, the diagnostic accuracy of transcranial Doppler, contrast transthoracic and transesophageal echocardiography in the diagnosis of left–fright shunt and PFO; and discuss the indications to medical treatment and percutaneous closure of PFO. Methods All studies published in the literature on PFO and cryptogenic stroke are considered and discussed. Results We define an appropriate diagnostic and clinical management of PFO patients with cryptogenic stroke. Conclusion After many years of interest on PFO and many concluded studies, there are still no definitive data. However, we are on good track for an appropriate management of PFO patients and cryptogenic stroke
Crying Time and RORÎł/FOXP3 Expression in Lactobacillus reuteri DSM17938-Treated Infants with Colic: A Randomized Trial
Objectives To evaluate crying time, retinoid-related orphan receptor-γ (RORγ) and forkhead box P3 (FOXP3) messenger RNA levels (transcription factors that can modulate T cell responses to gut microbes), and to investigate gut microbiota and fecal calprotectin in infants treated with Lactobacillus reuteri for infantile colic. Study design A double-blind, placebo-controlled randomized trial was conducted in primary care in Torino from August 1, 2015 to September 30, 2016. Patients suffering from infantile colic were randomly assigned to receive daily oral L reuteri (1 × 10 8  colony forming unit) or placebo for 1 month. Daily crying times were recorded in a structured diary. FOXP3 and RORγ messenger RNA in the peripheral blood was assessed with real-time TaqMan reverse transcription polymerase chain reaction. Gut microbiota and fecal calprotectin were evaluated. Results After infants with colic were supplemented with L reuteri DSM 17938 for 30 days, crying times were significantly shorter among infants with colic in the probiotic group compared with infants in the placebo group (74.67 ± 25.04 [IQR = 79] minutes /day vs 147.85 [IQR = 135] minutes /day [ P  = .001]). The FOXP3 concentration increased significantly ( P  = .009), resulting in decreased RORγ/FOXP3 ratios: 0.61 (IQR = 0.60) at day 0 and 0.48 (IQR = 0.28) at day 30 ( P  = .028). Furthermore, the probiotic increased the percentage of Lactobacillus ( P  = .049) and decreased fecal calprotectin ( P  = .0001). Conclusions Infants with colic treated with L reuteri for 30 days had a significantly decreased crying time and an increased FOXP3 concentration, resulting in a decreased RORγ/FOXP3 ratio. The treatment reduced fecal calprotectin. Trial registration ClinicalTrials.gov : NCT00893711
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