%0 Journal Article %1 WOS:000315322900018 %A Foucquier, A %A Filoche, M %A Moreira, A A %A Jr., J S Andrade %A Arbia, G %A Sapoval, B %C PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS %D 2013 %I ELSEVIER SCIENCE BV %J RESPIRATORY PHYSIOLOGY & NEUROBIOLOGY %K Acinus; Alveolar Diffusion Exercise; Membrane exchange; gas; limitation; permeability} {Gas %N 3 %P 625-638 %R 10.1016/j.resp.2012.10.013 %T A first principles calculation of the oxygen uptake in the human pulmonary acinus at maximal exercise %V 185 %X It has recently been shown that the acinus can have a reduced efficiency due to a ``screening effect'' governed by the ratio of oxygen diffusivity to membrane permeability, the gas flow velocity, as well as the size and configuration of the acinus. We present here a top to bottom calculation of the functioning of a machine acinus at exercise that takes this screening effect into account It shows that, given the geometry and the breathing dynamics of real acini, respiration can be correlated to a single equivalent parameter that we call the integrative permeability. In particular we find that both (V) over dot(O2,max) and PA(O2) depend on this permeability in a non-linear manner. Numerical solutions of dynamic convection-diffusion equations indicate that only a narrow range of permeability values is compatible with the experimental measurements of PA(O2) and (V) over dot(O2,max). These permeability values are significantly smaller than those found in the literature. In a second step, we present a new type of evaluation of the diffusive permeability, yielding values compatible with the top to bottom approach, but smaller than the usual morphometric value. (C) 2012 Elsevier B.V. All rights reserved.

@article{WOS:000315322900018, abstract = {It has recently been shown that the acinus can have a reduced efficiency due to a ``screening effect'' governed by the ratio of oxygen diffusivity to membrane permeability, the gas flow velocity, as well as the size and configuration of the acinus. We present here a top to bottom calculation of the functioning of a machine acinus at exercise that takes this screening effect into account It shows that, given the geometry and the breathing dynamics of real acini, respiration can be correlated to a single equivalent parameter that we call the integrative permeability. In particular we find that both (V) over dot(O2,max) and PA(O2) depend on this permeability in a non-linear manner. Numerical solutions of dynamic convection-diffusion equations indicate that only a narrow range of permeability values is compatible with the experimental measurements of PA(O2) and (V) over dot(O2,max). These permeability values are significantly smaller than those found in the literature. In a second step, we present a new type of evaluation of the diffusive permeability, yielding values compatible with the top to bottom approach, but smaller than the usual morphometric value. (C) 2012 Elsevier B.V. All rights reserved.}, added-at = {2022-05-23T20:00:14.000+0200}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, author = {Foucquier, A and Filoche, M and Moreira, A A and Jr., J S Andrade and Arbia, G and Sapoval, B}, biburl = {https://www.bibsonomy.org/bibtex/2f7fc82447de243f85483c9c0bbd783c1/ppgfis_ufc_br}, doi = {10.1016/j.resp.2012.10.013}, interhash = {27f95df6b8e0f0e743eb72793efdf55d}, intrahash = {f7fc82447de243f85483c9c0bbd783c1}, issn = {1569-9048}, journal = {RESPIRATORY PHYSIOLOGY & NEUROBIOLOGY}, keywords = {Acinus; Alveolar Diffusion Exercise; Membrane exchange; gas; limitation; permeability} {Gas}, number = 3, pages = {625-638}, publisher = {ELSEVIER SCIENCE BV}, pubstate = {published}, timestamp = {2022-05-23T20:00:14.000+0200}, title = {A first principles calculation of the oxygen uptake in the human pulmonary acinus at maximal exercise}, tppubtype = {article}, volume = 185, year = 2013 }