A new role for exhaled nitric oxide as a functional marker of peripheral airway caliber changes: a theoretical study

Though considered as an inflammation marker, exhaled nitric oxide (FENO) was shown to be sensitive to airway caliber changes to such an extent that it might be considered as a marker of them. It is thus important to understand how these changes and their localization mechanically affect the total NO flux penetrating the airway lumen (JawNO), hence FENO, independently from any inflammatory status change. A new model was used which simulates NO production, consumption and diffusion inside the airway epithelium wall, then, NO excretion through the epithelial wall into the airway lumen and, finally, its axial transport by diffusion and convection in the airway lumen. This model may also consider the presence of a mucus layer coating the epithelial wall. Simulations were performed that showed the great sensitivity of JawNO to peripheral airways caliber changes. Moreover, FENO showed distinct behaviors depending on the location of the caliber change. Considering a bronchodilation, absence of FENO change was associated with dilation of central airways, FENO increase with dilation up to pre-acinar small airways, and FENO decrease with intra-acinar dilation due to amplification of the back-diffusion flux. The presence of a mucus layer was also shown to play a significant role in FENO changes. Altogether, the present work provides theoretical evidences that specific FENO changes in acute situations are linked to specifically located airway caliber changes in the lung periphery. This opens the way for a new role for FENO as a functional marker of peripheral airway caliber change

Survey Paper: Mobility Management in Heterogeneous Wireless Networks

AbstractEver increasing user demands and development of modern communication technologies have led to the evolution of communication networks from 1st Generation (1G) network to 4G heterogeneous networks. Further, 4G with heterogeneous network environment will provide features such as, “Always Best Connected”, “Anytime Anywhere” and seamless communication. Due to diverse characteristics of heterogeneous networks such as bandwidth, latency, cost, coverage and Quality of Service (QoS) etc., there are several open and unsolved issues namely mobility management, network administration, security etc. Hence, Designing proficient mobility management to seamlessly integrate heterogeneous wireless networks with all-IP is the most challenging issue in 4G networks. Mobile IPv6 (MIPv6) developed by Internet Engineering Task Force (IETF) has mobility management for the packet-switched devices of homogeneous wireless networks. Further, mobility management of homogeneous networks depends on network related parameter i.e., Received Signal Strength (RSS). However the mobility management of heterogeneous networks, not only depends on network related parameters, but also on terminal-velocity, battery power, location information, user-user profile & preferences and service-service capabilities & QoS etc. Designing mobility management with all-IP, while, considering issues such as context of networks, terminal, user and services is the main concern of industry and researchers in the current era

New analysis of the mechanisms controlling the bronchial mucus balance

International audienceLining the bronchi in the lung, the mucus constitutes a protective layer from harmful pathogens and particles. Its displacement due to the coordinated beating of the bronchial epithelium cilia contributes to its clearance from the lung. As this mucociliary clearance is impaired in numerous pathologies, a comprehensive understanding of this process is critical. A simple mass balance over the mucus layer in an airway suggests that the cilia beating, on its own, is not sufficient enough for controlling the bronchial mucus balance in the entire lung. In this article, we show through a mathematical modeling approach that the evaporation of the water contained in the mucus layer could act as a control mechanism of the mucus balance. Furthermore, we suggest that other control mechanisms act in parallel to evaporation to maintain the mucus balance. Our model and results could be useful in the study and management of several mucus-related airway diseases , such as cystic fibrosis or exercise-induced asthma

Etude de la distribution de la ventilation dans la périphérie du poumon: application à la détection d'altérations de structure et de fonction

Doctorat en sciences médicalesinfo:eu-repo/semantics/nonPublishe

Etude de la distribution de la ventilation dans la périphérie du poumon: application à la détection d'altérations de structure et de fonction

Doctorat en sciences médicalesinfo:eu-repo/semantics/nonPublishe

Improvement of asthma control assessed by exhaled nitric oxide: a real life longitudinal study

info:eu-repo/semantics/nonPublishe

Asthma control is not related to large airways function

info:eu-repo/semantics/nonPublishe

Asthma control and exhaled nitric oxide in the real life

info:eu-repo/semantics/nonPublishe

Evaluation de la qualité de vie dans l’asthme par le monoxyde d’azote exhalé

info:eu-repo/semantics/nonPublishe