Search results for "RESPIRATORY SYSTEM"
showing 10 items of 1829 documents
Cardiovascular and respiratory variability during orthostatic and mental stress: A comparison of entropy estimators
2017
The aim of this study is to characterize cardiovascular and respiratory signals during orthostatic and mental stress as reflected in indices of entropy and complexity, providing a comparison between the performance of different estimators. To this end, the heart rate variability, systolic blood pressure, diastolic blood pressure and respiration time series were extracted from the recordings of 61 healthy volunteers undergoing a protocol consisting of supine rest, head-up tilt test and mental arithmetic task. The analysis was performed in the information domain using measures of entropy and conditional entropy, estimated through model-based (linear) and model-free (binning, nearest neighbor)…
Polymeric drug delivery micelle-like nanocarriers for pulmonary administration of beclomethasone dipropionate
2017
In this paper, the potential of novel polymeric micelles as drug delivery systems for Beclomethasone Dipropionate (BDP) administration into the lung is investigated. These nanostructures are obtained starting from α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA), which was subsequently functionalized with O-(2-aminoethyl)-Oâ-methylpolyethylenglycole (PEG2000), ethylenediamine (EDA) and lipoic acid (LA), obtaining PHEA-PEG2000-EDA-LA graft copolymer. Empty and drug-loaded micelles possess adequate chemical-physical characteristics for pulmonary administration such as spherical shape, slightly positive surface charge and mean size of about 200 nm. Besides, BDP-loaded micelles, obtained …
Study of aortic dissections treatment. Segmentation, simulation and valiadation of surgical results
2019
Nowadays, Computational Fluid Dynamics (CFD) it’s seen as the new trend in the management of aortic pathologies. Together with visualization capabilities of cardiovascular magnetic resonance (CMR) and computed tomography (CT) imaging, real time segmentation (volumetric) models further used as meshes in Computational Fluid Dynamic supply to the clinicians an innovative and extensive decision-making system. In the present paper, we identified and analysed the clinical indicators (lumens diameters, fenestrated area and blood volume) monitored by clinicians to evaluate the patient’ condition before and after the intervention. In order to achieve the targeted aims, we used CT scans as input data…
Quantification of Lung Volume at Different Tidal Volumes and Positive End-Expiratory Pressures in a Porcine Model by Using Retrospective Respiratory …
2008
PURPOSE: This feasibility study in healthy animals should prove the concept that it is possible to quantitatively assess the effects of different ventilatory settings on the lung parenchyma during ongoing ventilation in respiratory gated 4-dimensional (D)-computed tomography (CT). For this purpose, the influence of different tidal volumes and positive end-expiratory pressure (PEEP) on quantitative assessment of lung volumes (LVs) and lung compartments was analyzed. METHODS: Five anesthetized and ventilated (20 breaths/min, inspiratory/expiratory ratio of 1:2) healthy pigs underwent 16-row multidetector CT with retrospective respiratory gating using a noncontact charge-coupled device camera …
Analysis of intrapulmonary O2concentration by MR imaging of inhaled hyperpolarized helium-3
1999
Inhalation of hyperpolarized 3He allows magnetic resonance imaging (MRI) of ventilated airspaces.3He hyperpolarization decays more rapidly when interacting with paramagnetic O2. We describe a method for in vivo determination of intrapulmonary O2 concentrations ([O2]) based on MRI analysis of the fate of measured amounts of inhaled hyperpolarized3He in imaged regions of the lung. Anesthetized pigs underwent controlled normoventilation in a 1.5-T MRI unit. The inspired O2 fraction was varied to achieve different end-tidal [O2] fractions ([Formula: see text]). With the use of a specifically designed applicator,3He (100 ml, 35–45% polarized) was administered at a predefined time within single …
Performance of EasyBreath® Decathlon Snorkeling mask for Delivering Continuous Positive Airway Pressure
2020
ABSTRACTBackgroundDuring the COVID-19 pandemic, the need for noninvasive respiratory support devices has dramatically increased, sometimes exceeding hospital capacity. The full-face Decathlon snorkeling mask, EasyBreath® (EB® mask), has been adapted to deliver continuous positive airway pressure (CPAP) as an emergency respiratory interface. We aimed to assess the performance of this modified EB® mask.MethodsCPAP set at 5, 10, and 15 cmH2O was delivered to 10 healthy volunteers with a high-flow system generator set at 40, 80, and 120 L min-1 and with a turbine-driven ventilator during both spontaneous and loaded (resistor) breathing. Inspiratory CO2 partial pressure (PiCO2), pressure inside …
On the origin and systematics of the northern African wood mouse (<i>Apodemus sylvaticus</i>) populations: a comparative study of mtDNA r…
2001
Conflicting hypotheses have been formulated regarding the origin of wood mouse (Apodemus sylvaticus) populations in northern Africa. In this study, the mtDNA restriction patterns of mice (n = 28) collected in Tunisia and Morocco are compared with those of representatives from southern Europe (n = 102). The neighbour-joining tree confirms the existence of the three lineages previously found in the Mediterranean area: western, TyrrhenianBalkan, and Sicilian. The western group is isolated from the two others, with bootstrap values of 89 and 95%. Northern African patterns are included in the western group. Their variability is low, the same pattern being shared by five Tunisian and all Morocca…
Seven Mathematical Models of Hemorrhagic Shock
2021
Although mathematical modelling of pressure-flow dynamics in the cardiocirculatory system has a lengthy history, readily finding the appropriate model for the experimental situation at hand is often a challenge in and of itself. An ideal model would be relatively easy to use and reliable, besides being ethically acceptable. Furthermore, it would address the pathogenic features of the cardiovascular disease that one seeks to investigate. No universally valid model has been identified, even though a host of models have been developed. The object of this review is to describe several of the most relevant mathematical models of the cardiovascular system: the physiological features of circulator…
ChemInform Abstract: Ganodermycin, a Novel Inhibitor of CXCL10 Expression from Ganoderma applanatum.
2012
Ganodermycin (I), a novel inhibitor of CXCL10 expression, is isolated from Ganoderma applanatum.
CT densitometry-based differential diagnosis between emphysematous and non-emphysematous lungs in elderly patients.
2010
Purpose Methods and Materials Results Conclusion References Personal Information