Ageing and endurance training effects on quantity and quality of pulmonary vascular bed in healthy men

International audienceIt has recently been demonstrated that in healthy individuals, peak oxygen consumption is associated with a greater pulmonary capillary blood volume and a more distensible pulmonary circulation. Our cross-sectional study suggests that, in healthy men aged 20 to 60 years (n = 63), endurance sport practice (vigorous-intensity domain of the International Physical Activity Questionnaire) is associated with better quantity (pulmonary capillary blood volume) and quality (slope of increase in lung diffusion for carbon monoxide on exercise) of the pulmonary vascular bed, partly counterbalancing the deleterious effects of ageing, which remains to be demonstrated in a prospective longitudinal design

Determination of aggregates soot size distribution by analysis of extinction and angular static light scattering spectra

Le but de ce travail est de déterminer par méthodes optiques la distribution de taille (pdf) des nanoparticules de suie, agrégats de morphologie fractale. Après des études préliminaires qui utilisent DDSCAT pour valider la théorie RDG-FA et permettent de convertir un rayon de giration en rayon de mobilité, deux diagnostics optiques sont étudiés. Le premier consiste à exploiter une mesure d'extinction spectrale de la lumière. Nous montrons que pour exploiter ce signal, il faut connaître les propriétés optiques des suies, leur préfacteur et dimension fractale, la loi de distribution et le diamètre des sphérules primaires. Le second diagnostic tire parti de la mesure angulaire de la diffusion de la lumière. Nous montrons qu'il est possible de déterminer la pdf à l'aide de la mesure de diffusion à trois angles. Il faut supposer la loi de distribution et la dimension fractale. Cette deuxième approche, in-situ, est plus appropriée que la première pour déterminer optiquement la pdf des suies.The objective of this thesis is to determine by optical methods the soot size distribution. Soot are fractal-like morphology nanoparticles aggregates. After preliminary studies which used DDSCAT to validate the RDG-FA theory and allow converting gyration radius to mobility radius, two optical approaches are considered. The first one is based on a measure of spectral light extinction by soot. To exploit this signal, the knowledge of soot optical properties, fractal prefactor, type of law distribution, fractal dimension and primary spheres diameters are needed. The second one exploits the measure of angular scattering by particles. It is possible to determine the size distribution by using scattering measurement at only three angles. However, it's necessary to assume the type of law distribution and the fractal dimension. This second approach is more appropriate than the first one to determine optically the size distribution of soot and hold the interest to be in-situ

Détermination de la distribution de taille des nanoparticules de suie par analyse du spectre d'extinction et de diffusion angulaire de la lumière

The objective of this thesis is to determine by optical methods the soot size distribution. Soot are fractal-like morphology nanoparticles aggregates. After preliminary studies which used DDSCAT to validate the RDG-FA theory and allow converting gyration radius to mobility radius, two optical approaches are considered. The first one is based on a measure of spectral light extinction by soot. To exploit this signal, the knowledge of soot optical properties, fractal prefactor, type of law distribution, fractal dimension and primary spheres diameters are needed. The second one exploits the measure of angular scattering by particles. It is possible to determine the size distribution by using scattering measurement at only three angles. However, it's necessary to assume the type of law distribution and the fractal dimension. This second approach is more appropriate than the first one to determine optically the size distribution of soot and hold the interest to be in-situ.Le but de ce travail est de déterminer par méthodes optiques la distribution de taille (pdf) des nanoparticules de suie, agrégats de morphologie fractale. Après des études préliminaires qui utilisent DDSCAT pour valider la théorie RDG-FA et permettent de convertir un rayon de giration en rayon de mobilité, deux diagnostics optiques sont étudiés. Le premier consiste à exploiter une mesure d'extinction spectrale de la lumière. Nous montrons que pour exploiter ce signal, il faut connaître les propriétés optiques des suies, leur préfacteur et dimension fractale, la loi de distribution et le diamètre des sphérules primaires. Le second diagnostic tire parti de la mesure angulaire de la diffusion de la lumière. Nous montrons qu'il est possible de déterminer la pdf à l'aide de la mesure de diffusion à trois angles. Il faut supposer la loi de distribution et la dimension fractale. Cette deuxième approche, in-situ, est plus appropriée que la première pour déterminer optiquement la pdf des suies

Formation et caractérisation in-situ des agrégats de suie

National audienc

Détermination de la distribution de taille des nanoparticules de suie par analyse du spectre d'extinction et de diffusion angulaire de la lumière

Le but de ce travail est de déterminer par méthodes optiques la distribution de taille (pdf) des nanoparticules de suie, agrégats de morphologie fractale. Après des études préliminaires qui utilisent DDSCAT pour valider la théorie RDG-FA et permettent de convertir un rayon de giration en rayon de mobilité, deux diagnostics optiques sont étudiés. Le premier consiste à exploiter une mesure d'extinction spectrale de la lumière. Nous montrons que pour exploiter ce signal, il faut connaître les propriétés optiques des suies, leur préfacteur et dimension fractale, la loi de distribution et le diamètre des sphérules primaires. Le second diagnostic tire parti de la mesure angulaire de la diffusion de la lumière. Nous montrons qu'il est possible de déterminer la pdf à l'aide de la mesure de diffusion à trois angles. Il faut supposer la loi de distribution et la dimension fractale. Cette deuxième approche, in-situ, est plus appropriée que la première pour déterminer optiquement la pdf des suies.The objective of this thesis is to determine by optical methods the soot size distribution. Soot are fractal-like morphology nanoparticles aggregates. After preliminary studies which used DDSCAT to validate the RDG-FA theory and allow converting gyration radius to mobility radius, two optical approaches are considered. The first one is based on a measure of spectral light extinction by soot. To exploit this signal, the knowledge of soot optical properties, fractal prefactor, type of law distribution, fractal dimension and primary spheres diameters are needed. The second one exploits the measure of angular scattering by particles. It is possible to determine the size distribution by using scattering measurement at only three angles. However, it's necessary to assume the type of law distribution and the fractal dimension. This second approach is more appropriate than the first one to determine optically the size distribution of soot and hold the interest to be in-situ.ROUEN-INSA Madrillet (765752301) / SudocSudocFranceF

Measurement of aggregate size distribution by inversion of angular light scattering

The aim of this work is to propose a new method for determining the size distribution of submicronic particles by inversion of the measured angular scattering of light. This method relies on the determination of a function Rg*. by angular scattering. The variation of this function informs us about the polydispersity of the aggregates size. We show that, by supposing the nature of the size distributions (lognormal), it is possible to determine the governing parameters of these distributions

Measurement of aggregates' size distribution by angular light scattering

International audienceno abstrac

Endurance-training in healthy men is associated with lesser exertional breathlessness that correlates with circulatory-muscular conditioning markers in a cross-sectional design.

International audienceWhether exertional dyspnoea can be attributed to poor circulatory-muscular conditioning is a difficult clinical issue. Because criteria of poor conditioning such as low oxygen pulse, low ventilatory threshold or high heart rate/oxygen consumption slope can be observed in heart or lung diseases and are not specific to conditioning, we assessed the relationships between physical exercise, conditioning and exertional breathlessness in healthy subjects, in whom the aforementioned criteria can confidently be interpreted as reflecting conditioning. To this end, healthy males with either low (inactive men, n = 31) or high (endurance-trained men, n = 31) physical activity evaluated using the International Physical Activity Questionnaire (IPAQ) underwent spirometry and incremental exercise testing with breathlessness assessment using Borg scale. No significant breathlessness was reported before the ventilatory threshold in the two groups. Peak breathlessness was highly variable, did not differ between the two groups, was not related to any conditioning criterion, but correlated with peak respiratory rate. Nevertheless, endurance-trained subjects reported lower breathlessness at the same ventilation levels in comparison with inactive subjects. Significant but weak associations were observed between isoventilation breathlessness and physical activity indices (Borg at 60 L/min and total IPAQ scores, rho = -0.31, p = 0.020), which were mainly attributable to the vigorous domain of physical activity, as well as with conditioning indices (Borg score at 60 L.min(-1) and peak oxygen pulse or heart rate/oxygen consumption slope, rho = -0.31, p = 0.021 and rho = 0.31, p = 0.020; respectively). In conclusion, our data support a weak relationship between exertional breathlessness and circulatory-muscular conditioning, the later being primarily related to vigorous physical activity

Relationships between respiratory and airway resistances and activity-related dyspnea in patients with chronic obstructive pulmonary disease

Bruno Mahut1,2, Aurore Caumont-Prim3,4, Laurent Plantier1,5, Karine Gillet-Juvin1,6, Etienne Callens1, Olivier Sanchez5,6, Brigitte Chevalier-Bidaud3, Plamen Bokov1, Christophe Delclaux1,5,71Assistance Publique – Hôpitaux de Paris (AP-HP), Hôpital Européen Georges Pompidou, Service de Physiologie – Clinique de la Dyspnée, F-75015 Paris, France; 2Cabinet La Berma, 4 avenue de la Providence; F-92160 Antony, France; 3AP-HP, Hôpital Européen Georges Pompidou, Unité d'Épidémiologie et de Recherche Clinique, F-75015 Paris, France; 4INSERM, Centre d'Investigation Épidémiologique 4, F-75015 Paris, France; 5Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, F-75015 Paris, France; 6AP-HP, Hôpital Européen Georges Pompidou, Service de Pneumologie; F-75015 Paris, France; 7CIC 9201 Plurithématique, Hôpital Européen Georges Pompidou, F-75015 Paris, FranceBackground: The aims of the study were: (1) to compare numerical parameters of specific airway resistance (total, sRawtot, effective, sRaweff and at 0.5 L • s-1, sRaw0.5) and indices obtained from the forced oscillation technique (FOT: resistance extrapolated at 0 Hz [Rrs0 Hz], mean resistance [Rrsmean], and resistance/frequency slope [Rrsslope]) and (2) to assess their relationships with dyspnea in chronic obstructive pulmonary disease (COPD).Methods: A specific statistical approach, principal component analysis that also allows graphic representation of all correlations between functional parameters was used. A total of 108 patients (mean ± SD age: 65 ± 9 years, 31 women; GOLD stages: I, 14; II, 47; III, 39 and IV, 8) underwent spirometry, body plethysmography, FOT, and Medical Research Council (MRC) scale assessments.Results: Principal component analysis determined that the functional parameters were described by three independent dimensions (airway caliber, lung volumes and their combination, specific resistance) and that resistance parameters of the two techniques were not equivalent, obviously. Correlative analyses further showed that Rawtot and Raweff (and their specific resistances) can be considered as equivalent and correlated with indices that are considered to explore peripheral airways (residual volume (RV), RV/ total lung capacity (TLC), Rrsslope), while Rrsmean and Raw0.5 explored more central airways. Only specific resistances taking into account the specific resistance loop area (sRawtot and sRaweff) and Rrsslope were statistically linked to dyspnea.Conclusion: Parameters obtained from both body plethysmography and FOT can explore peripheral airways, and some of these parameters (sRawtot, sRaweff, and Rrsslope) are linked to activity-related dyspnea in moderate to severe COPD patients.Keywords: body plethysmography, forced oscillation technique, principal component analysi