Search results for "Forced"
showing 10 items of 500 documents
Genome-wide association analysis identifies six new loci associated with forced vital capacity
2014
Forced vital capacity (FVC), a spirometric measure of pulmonary function, reflects lung volume and is used to diagnose and monitor lung diseases. We performed genome-wide association study meta-analysis of FVC in 52,253 individuals from 26 studies and followed up the top associations in 32,917 additional individuals of European ancestry. We found six new regions associated at genome-wide significance (P <5 x 10(-8)) with FVC in or near EFEMP1, BMP6, MIR129-2-HSD17B12, PRDM11, WWOX and KCNJ2. Two loci previously associated with spirometric measures (GSTCD and PTCH1) were related to FVC. Newly implicated regions were followed up in samples from African-American, Korean, Chinese and Hispani…
A model-based approach for assessing bronchodilator responsiveness in children: The conventional cutoff revisited
2020
An increase in FEV1 >=12% has been proposed in international guidelines as a clue to airway reversibility for diagnosing asthma in both adults and children. However, the validity of this cut-off has been questioned in the pediatric population. The aim of this study was to provide evidence that different cut-off values in BDR may be associated with better performance in discriminating among outpatient children with naïve asthma (A) and without asthma (NA). We compared three approaches: i) the conventional cutoff (12%); ii) the cut-off estimated by Youden's criteria; and iii) the cut-off based on a model-driven approach. we found that the conventional cut-off of 12% showed poor sensitivity in…
Determinants of Allergic Sensitization, Asthma and Lung Function: Results from a Cross-Sectional Study in Italian Schoolchildren
2020
Prenatal smoking exposure and early-life respiratory infections are major determinants of asthma during childhood. We investigate the factors influencing allergic sensitization (AS), asthma, and lung function in children and the balance between individual and environmental characteristics at different life stages. 1714 children aged 7&ndash
Measuring lung function in asthmatic children: A spirometry and forced oscillation technique (FOT) comparison
2016
Background: Spirometry is the most common pulmonary function test used in asthma diagnosing. However, it requires good patient co-operation. FOT has gained increasing attention for the measurement of pulmonary function in children because it is performed at steady state breathing. Aim: To compare spirometry and FOT in order to discriminate severity of asthma according to GINA. Methods: Spirometry and FOT were performed in 176 out-patient asthmatic children (5-16 year), 100 (57%) with naive Persistent Asthma (PA) and 76 (43%) with Intermittent Asthma (IA), consecutively enrolled at the IBIM pediatric clinic. Two principal component analyses (PCA) were performed, the first (PCA1) based on FEV…
Nonlinear parametric quantile models
2020
Quantile regression is widely used to estimate conditional quantiles of an outcome variable of interest given covariates. This method can estimate one quantile at a time without imposing any constraints on the quantile process other than the linear combination of covariates and parameters specified by the regression model. While this is a flexible modeling tool, it generally yields erratic estimates of conditional quantiles and regression coefficients. Recently, parametric models for the regression coefficients have been proposed that can help balance bias and sampling variability. So far, however, only models that are linear in the parameters and covariates have been explored. This paper …
Experimental Tests of Fatigue Induced Delamination in Gfrp and Cfrp Laminates
2007
This work deals with the experimental analysis of the delamination phenomena in various composite materials under different loading conditions. Quasi-static and fatigue tests are performed on specimens made of glass-fibre reinforced plastic (GFRP) and carbon-fibre reinforced plastic (CFRP). In particular, under both quasi-static and fatigue loading, single fracture modes I and II (using standard DCB and ENF test configurations) and mixed modes I+II (using the MMB test configuration) with several mode mixtures, have been analysed. Further experiments of delamination growth with mode mixture that varies with the crack length, will be performed.
Experimental investigation on BFRCM confinement of masonry cylinders and comparison with BFRP system
2021
Abstract Fabric reinforced cementitious mortar (FRCM) materials have started to be employed during the last years with the aim of overcoming the drawbacks related to the use of fibre reinforced polymer (FRP) composites, proving to be potentially suitable for strengthening masonry structures. Moreover, the will to develop materials able to guarantee a certain degree of sustainability without renouncing to adequate mechanical properties has drawn the attention to the use of basalt fibres, which appear to be a valid alternative to carbon or glass fibres. This work presents an experimental investigation on a basalt FRCM (BFRCM) system to confine circular masonry columns, aimed at evaluating the…
Strength and strain enhancements of concrete columns confined with FRP sheets
2004
The compressive behavior up to failure of short concrete members reinforced with fiber reinforced plastic (FRP) is investigated. Rectangular cross-sections are analysed by means of a simplified elastic model, able also to explain stress-concentration. The model allows one to evaluate the equivalent uniform confining pressure in ultimate conditions referred to the effective confined cross-section and to the effective stresses in FRP along the sides of section; consequently, it makes it possible to determine ultimate strain and the related bearing capacity of the confined member corresponding to FRP failure. The effect of local reinforcements constitute by single strips applied at corners bef…
Investigation on the influence of the surface resin rich layer on the thermoelastic signal from different composite laminate lay-ups
2006
This work presents a set of experimental results based on the measured thermoelastic signal from GRP composite coupons adopting different lay-ups. A comparison is made with the thermoelastic signal predicted by two different analytical models: one based on the classical law of the thermoelastic effect for orthotropic materials, and the other based on a novel theory accounting for the presence of a resin layer on the external surface of the composite structure. The composite coupons were designed such to determine a significant difference in the predictions made by the two theoretical models. Experimental results have shown a far better match with the predictions based on the novel theory ac…
Equi-intensity across the SpectrumTM taste scales
2015
Abstract This work aimed to study the equi-intensity across the Spectrum™ taste scales. The approach consisted of a comparison of four reference points illustrating the same level of intensity across the scales using two very different methods: 2-alternative forced-choice (2-AFC) and Labeled Magnitude Scale (LMS). The comparisons across these scales were based on caffeine, citric acid, sodium chloride, sucrose, and monosodium glutamate in water solutions, at different concentrations, prepared according to the guidelines given for the Spectrum™ method. A scale concerning the umami taste, designed in the spirit of the Spectrum™ scales, was also studied in this work. Both procedures produced s…