22 research outputs found
Airway inflammation in patients affected by obstructive sleep apnea
Obstructive sleep apnea (OSA) is characterised by repetitive episodes of upper airway occlusion during sleep. OSA has been shown to be associated with a variable degree of nasal inflammation, uvula mucosal congestion and airway hyperreactivity. The upper airway inflammation, whose clinical importance is uncertain, is characterised by leukocytes infiltration and interstitial oedema. In addition, recent data has shown the presence of neutrophilic inflammation in the lower airways. The current opinion is that airway inflammation is caused by the local, repeated mechanical trauma related to the intermittent airway occlusion typical of the disease. Another potential mechanism involves the intermittent nocturnal hypoxemia that through the phenomenon of the ischemia- reperfusion injury may induce the production of oxygen free radicals and therefore cause local and systemic inflammation. Finally, a state of low-grade systemic inflammation may be related to obesity per se with the pro-inflammatory mediators synthesised in the visceral adipose cells. Several authors stress the role of circulating and local inflammatory mediators, such as proinflammatory cytokines, exhaled nitric oxide, pentane and 8-isoprostane as the determinants of inflammation in OSA
The extracellular matrix of the lung and airway responsiveness in asthma
The extracellular matrix is the main determinant of the structure and of mechanical behaviour of the lung. The extracellular matrix is also responsible for the mechanical interdependence between airway and parenchyma due to the alveolar attachments to the airways. Asthma is characterized by bronchial hyperresponsiveness, airway remodelling and inflammation, and an altered extracellular matrix may play a role in all these functional and structural abnormalities. The excessive airway narrowing observed in asthma may be related to the altered viscoelastic properties of lung parenchyma and airway wall, determining a decrease in the mechanical load opposing the airways’ smooth muscle contraction. Indeed, an altered extracellular matrix deposition in asthma in humans, has been demonstrated. In addition, in the asthmatic lung, the matrix seems to contribute to airway inflammation, airway remodelling, and to those alterations of the smooth muscle function of the airway and morphology typical of asthma
Brittle asthma
Brittle asthma is a clinical phenotype of the disease at the severe end of the spectrum. Type 1 brittle asthma is characterised by a maintained wide PEF variability (> 40% diurnal variation for > 50% of the time over a period of at least 150 days) despite considerable medical therapy including a dose of inhaled steroids of at least 1500 μg of beclomethasone or equivalent. Type 2 brittle asthma is characterised by sudden acute attacks occurring in less than three hours without an obvious trigger on a background of apparent normal airway function or well controlled asthma. Mechanisms behind the development of brittle asthma include smooth muscle contraction and edema of the airways, which are supported by chronic airway inflammation. Allergy reactions, impairment of local immunity, respiratory infections, psycho-social disorders and reduced perception of worsening airway function are the risk factors for brittle asthma. The diagnosis is based on the analysis of specific symptoms, role of triggers, personal or family history, measurement of lung function and PEF monitoring. Pharmacological treatment of type 1 brittle asthma in addition to the high doses of inhaled and/or oral steroids and bronchodilators includes subcutaneous injections of β2 agonist and inhalation of long acting β2 agonist. The treatment of patients with type 2 brittle asthma includes exclusion of allergen exposure, identification of triggers, self management and management of acute attacks
Revisiting Some Developments of Boundary Elements for Thick Plates in Brazil
This work reviews the developments of Boundary Element Method formulations to solve several types of plate bending problems, including non-linear bending. The formulation is developed and solved using the standard BEM procedure, and different integration approaches were discussed and tested. Object oriented implementation issues are commented. Results were obtained for linear and non-linear elastic bending as well as buckling of selected cases of thick plates, including cases of step variation in thickness under large displacements regime
Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV
Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7 fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale
Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV
Searches for supersymmetry (SUSY) are presented based on the electroweak pair production of neutralinos and charginos, leading to decay channels with Higgs, Z, and W bosons and undetected lightest SUSY particles (LSPs). The data sample corresponds to an integrated luminosity of about 19.5 fb(-1) of proton-proton collisions at a center-of-mass energy of 8 TeV collected in 2012 with the CMS detector at the LHC. The main emphasis is neutralino pair production in which each neutralino decays either to a Higgs boson (h) and an LSP or to a Z boson and an LSP, leading to hh, hZ, and ZZ states with missing transverse energy (E-T(miss)). A second aspect is chargino-neutralino pair production, leading to hW states with E-T(miss). The decays of a Higgs boson to a bottom-quark pair, to a photon pair, and to final states with leptons are considered in conjunction with hadronic and leptonic decay modes of the Z and W bosons. No evidence is found for supersymmetric particles, and 95% confidence level upper limits are evaluated for the respective pair production cross sections and for neutralino and chargino mass values
Airway inflammation in patients affected by obstructive sleep apnea syndrome
AbstractObstructive sleep apnea syndrome (OSAS) has been shown to be associated to upper airway inflammation. The object of the present study was to establish the presence of bronchial inflammation in OSAS subjects.In 16 subjects affected by OSAS, and in 14 healthy volunteers, airway inflammation was detected by the cellular analysis of the induced sputum.OSAS patients, as compared to control subjects, showed a higher percentage of neutrophils (66.7±18.9 vs. 25.8±15.6) (P<0.001) and a lower percentage of macrophages (29.4±18.4 vs. 70.8±15.3) (P<0.001). The percentage of eosinophils and lymphocytes were not significantly different in the two groups.OSAS subjects show bronchial inflammation characterized by a significant increase in neutrophils