Linear driving force (LDF) model is widely used in a diffusion process. However thismodel has inherent weakness. When the dimensionless time is less than 0.1, its relativeerror is up to 95%. In this paper a new concen...Linear driving force (LDF) model is widely used in a diffusion process. However thismodel has inherent weakness. When the dimensionless time is less than 0.1, its relativeerror is up to 95%. In this paper a new concentration profile is proposed, and then a newmodified LDF model (MLDF) is deduced. Compared with the exact solution ofintraparticle diffusion equation, the transient volume-average amount adsorbedcalculated from the MLDF is more accurate than that calculaled from the LDF modeL .Ifone takes ±10% relative error for the limit of validity of approximation, the new model isvalid when the dimensionless time is just larger than 0. 0002, while the LDF model is notvalid until the dimension time is large than 0.05. The new model is superior to the LDFmodel. The new concentration profiles corresponding to the MLDF model are much closeto the exact concentration profiles within a particle than the parabolic propescorresponding to the LDF model.展开更多
Nicotinamide adenine dinucleotide (NADH/NAD+) is involved in important biochemical reactions in human metabolism, including participation in energy production by mitochondria. The changes in fluorescence intensity as ...Nicotinamide adenine dinucleotide (NADH/NAD+) is involved in important biochemical reactions in human metabolism, including participation in energy production by mitochondria. The changes in fluorescence intensity as a function of time in response to blocking and releasing of blood flow in a forearm are used as a measure of oxygen transport with blood to the tissue, which directly correlates with the skin microcirculation status. In this paper, a non-invasive dynamic monitoring system based on blood flow-mediated skin fluorescence (FMSF) technology is developed to monitor the NADH fluorescence intensity of skin tissue during the process of blocking reactive hyperemia. Simultaneously, laser speckle contrast imaging (LSCI) and laser Doppler flowmetry (LDF) were used to observe blood flow, blood oxygen saturation (SOt2) and relative amount of hemoglobin (rHb) during the measurement process, which helped to explore NADH dynamics relevant physiological changes. A variety of parameters have been derived to describe NADH fluorescence curve based on the FMSF device. The experimental results are conducive to understanding the NADH measurement and the physiological processes related to it, which help FMSF to be a great avenue for in vivo physiological, clinical and pharmacological research on mitochondrial metabolism.展开更多
文摘Linear driving force (LDF) model is widely used in a diffusion process. However thismodel has inherent weakness. When the dimensionless time is less than 0.1, its relativeerror is up to 95%. In this paper a new concentration profile is proposed, and then a newmodified LDF model (MLDF) is deduced. Compared with the exact solution ofintraparticle diffusion equation, the transient volume-average amount adsorbedcalculated from the MLDF is more accurate than that calculaled from the LDF modeL .Ifone takes ±10% relative error for the limit of validity of approximation, the new model isvalid when the dimensionless time is just larger than 0. 0002, while the LDF model is notvalid until the dimension time is large than 0.05. The new model is superior to the LDFmodel. The new concentration profiles corresponding to the MLDF model are much closeto the exact concentration profiles within a particle than the parabolic propescorresponding to the LDF model.
文摘Nicotinamide adenine dinucleotide (NADH/NAD+) is involved in important biochemical reactions in human metabolism, including participation in energy production by mitochondria. The changes in fluorescence intensity as a function of time in response to blocking and releasing of blood flow in a forearm are used as a measure of oxygen transport with blood to the tissue, which directly correlates with the skin microcirculation status. In this paper, a non-invasive dynamic monitoring system based on blood flow-mediated skin fluorescence (FMSF) technology is developed to monitor the NADH fluorescence intensity of skin tissue during the process of blocking reactive hyperemia. Simultaneously, laser speckle contrast imaging (LSCI) and laser Doppler flowmetry (LDF) were used to observe blood flow, blood oxygen saturation (SOt2) and relative amount of hemoglobin (rHb) during the measurement process, which helped to explore NADH dynamics relevant physiological changes. A variety of parameters have been derived to describe NADH fluorescence curve based on the FMSF device. The experimental results are conducive to understanding the NADH measurement and the physiological processes related to it, which help FMSF to be a great avenue for in vivo physiological, clinical and pharmacological research on mitochondrial metabolism.
