scholarly journals Gas distribution in a two-compartment model ventilated in high-frequency percussive and pressure-controlled modes

2010 ◽  
Vol 36 (12) ◽  
pp. 2125-2131 ◽  
Author(s):  
Umberto Lucangelo ◽  
Agostino Accardo ◽  
Alessandro Bernardi ◽  
Massimo Ferluga ◽  
Massimo Borelli ◽  
...  
Keyword(s):  
High Frequency ◽  
Compartment Model ◽  
Gas Distribution ◽  
Two Compartment Model ◽  
Pressure Controlled

Gas distribution in a two-compartment model during volume or pressure ventilation: Role of elastic elements

2010 ◽  
Vol 171 (3) ◽  
pp. 225-231 ◽  
Author(s):  
Vittorio Antonaglia ◽  
Umberto Lucangelo ◽  
Giuseppe Ristagno ◽  
Simona Tantillo ◽  
Massimo Ferluga ◽  
...  
Keyword(s):  
Compartment Model ◽  
Gas Distribution ◽  
Two Compartment Model ◽  
Elastic Elements

scholarly journals Decomposition of High-Frequency Electrical Conductivity into Extracellular and Intracellular Compartments based on Two-Compartment Model using Low-to-High Multi-b Diffusion MRI

2020 ◽  
Author(s):  
Mun Bae Lee ◽  
Hyung Joong Kim ◽  
Oh-In Kwon
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
High Frequency ◽  
Compartment Model ◽  
Biological Tissues ◽  
Extracellular Medium ◽  
Two Compartment Model ◽  
Random Decision Forests ◽  
Human Experiments ◽  
Micro Structures

Abstract Background: As an object's electrical passive property, the electrical conductivity is proportional to the mobility and concentration of charged carriers that reflect the brain micro-structures. The measured Mb-DWI data by controlling the degree of applied diffusion weights can quantify the apparent mobility of water molecules within biological tissues. Without any external electrical stimulation, magnetic resonance electrical properties tomography (MREPT) techniques have successfully recovered the conductivity distribution at a Larmor-frequency. Methods: This work provides a non-invasive method to decompose the high-frequency conductivity into the extracellular medium conductivity based on a two-compartment model using multi-b diffusion-weighted imaging (Mb-DWI). To separate the intra- and extracellular micro-structures from the recovered high-frequency conductivity, we include higher b-values DWI and apply the random decision forests to stably determine the micro-structural diffusion parameters. Results: To demonstrate the proposed method, we conducted human experiments by comparing the results of reconstructed conductivity of extracellular medium and the conductivity in the intra-neurite and intra-cell body. Human experiments verify that the proposed method can recover the extracellular electrical properties from the high-frequency conductivity using a routine protocol sequence of MRI scan. Conclusion: We have proposed a method to decompose the electrical properties in the extracellular, intra-neurite, and soma compartments from the high-frequency conductivity map, reconstructed by solving the electro-magnetic equation with measured B1 phase signals.

scholarly journals Decomposition of high-frequency electrical conductivity into extracellular and intracellular compartments based on two-compartment model using low-to-high multi-b diffusion MRI

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Mun Bae Lee ◽  
Hyung Joong Kim ◽  
Oh In Kwon
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
High Frequency ◽  
Compartment Model ◽  
Biological Tissues ◽  
Extracellular Medium ◽  
Two Compartment Model ◽  
Random Decision Forests ◽  
Human Experiments ◽  
Micro Structures

Abstract Background As an object’s electrical passive property, the electrical conductivity is proportional to the mobility and concentration of charged carriers that reflect the brain micro-structures. The measured multi-b diffusion-weighted imaging (Mb-DWI) data by controlling the degree of applied diffusion weights can quantify the apparent mobility of water molecules within biological tissues. Without any external electrical stimulation, magnetic resonance electrical properties tomography (MREPT) techniques have successfully recovered the conductivity distribution at a Larmor-frequency. Methods This work provides a non-invasive method to decompose the high-frequency conductivity into the extracellular medium conductivity based on a two-compartment model using Mb-DWI. To separate the intra- and extracellular micro-structures from the recovered high-frequency conductivity, we include higher b-values DWI and apply the random decision forests to stably determine the micro-structural diffusion parameters. Results To demonstrate the proposed method, we conducted phantom and human experiments by comparing the results of reconstructed conductivity of extracellular medium and the conductivity in the intra-neurite and intra-cell body. The phantom and human experiments verify that the proposed method can recover the extracellular electrical properties from the high-frequency conductivity using a routine protocol sequence of MRI scan. Conclusion We have proposed a method to decompose the electrical properties in the extracellular, intra-neurite, and soma compartments from the high-frequency conductivity map, reconstructed by solving the electro-magnetic equation with measured B1 phase signals.

Two-Compartment Model of Cholesterol Kinetics for Establishment of Treatment Strategy of LDL Apheresis in Nephrotic Hypercholesterolemia

1994 ◽  
Vol 12 (6) ◽  
pp. 317-326 ◽  
Author(s):  
Masatomo Yashiro ◽  
Eri Muso ◽  
Munehiro Matsushima ◽  
Ryoichi Nagura ◽  
Kenji Sawanishi ◽  
...  
Keyword(s):  
Treatment Strategy ◽  
Compartment Model ◽  
Ldl Apheresis ◽  
Two Compartment Model

Clearance and Non-Invasive Determination of the Hepatic Extraction of Indocyanine Green in Baboons and Man

1983 ◽  
Vol 64 (2) ◽  
pp. 207-212 ◽  
Author(s):  
S. L. Grainger ◽  
P. W. N. Keeling ◽  
I. M. H. Brown ◽  
J. H. Marigold ◽  
R. P. H. Thompson
Keyword(s):  
Indocyanine Green ◽  
Accurate Determination ◽  
Liver Blood Flow ◽  
Compartment Model ◽  
Hepatic Extraction ◽  
Non Invasive ◽  
Two Compartment Model ◽  
Hepatic Extraction Ratio ◽  
Plasma Disappearance Curve

1. The disposition of an intravenous bolus of indocyanine green (ICG) has been studied in healthy man and baboons using a novel analysis of a two compartment pharmacokinetic model. 2. This analysis enabled the hepatic extraction ratio (ER) of dye to be determined solely from the plasma disappearance curve, and the ER determined did not differ from that measured by hepatic vein catheterization. 3. When compared with clearance measured at steady state, the two compartment model gave a significantly more accurate determination of plasma clearance than did the conventional one compartment model. 4. It is concluded that, in health, liver blood flow may be calculated accurately and noninvasively after a single intravenous injection of ICG.

scholarly journals Serum bactericidal activities and comparative pharmacokinetics of meropenem and imipenem-cilastatin.

1996 ◽  
Vol 40 (1) ◽  
pp. 105-109 ◽  
Author(s):  
M Dreetz ◽  
J Hamacher ◽  
J Eller ◽  
K Borner ◽  
P Koeppe ◽  
...  
Keyword(s):  
Compartment Model ◽  
Pharmacokinetic Parameters ◽  
Time Curve ◽  
Dose Administration ◽  
Microdilution Method ◽  
Two Compartment Model ◽  
Elimination Half ◽  
Renal Clearances ◽  
The Mean ◽  
Bactericidal Activities

The pharmacokinetics and serum bactericidal activities (SBAs) of imipenem and meropenem were investigated in a randomized crossover study. Twelve healthy male volunteers received a constant 30-min infusion of either 1 g of imipenem plus 1 g of cilastatin or 1 g of meropenem. The concentrations of the drugs in serum and urine were determined by bioassay and high-pressure liquid chromatography. Pharmacokinetic parameters were based on an open two-compartment model and a noncompartmental technique. At the end of infusion, the mean concentrations of imipenem and meropenem measured in serum were 61.2 +/- 9.8 and 51.6 +/- 6.5 mg/liter, respectively; urinary recoveries were 48.6% +/- 8.2% and 60.0% +/- 6.5% of the dose in 12 h, respectively; and the areas under the concentration-time curve from time zero to infinity were 96.1 +/- 14.4 and 70.5 +/- 10.3 mg.h/liter, respectively (P < or = 0.02). Imipenem had a mean half-life of 66.7 +/- 10.4 min; that of meropenem was 64.4 +/- 6.9 min. The volumes of distribution at steady state of imipenem and meropenem were 15.3 +/- 3.3 and 18.6 +/- 3.0 liters/70 kg, respectively, and the mean renal clearances per 1.73 m2 were 85.6 +/- 17.6 and 144.6 +/- 26.0 ml/min, respectively. Both antibiotics were well tolerated in this single-dose administration study. The SBAs were measured by the microdilution method of Reller and Stratton (L. B. Reller and C. W. Stratton, J. Infect. Dis. 136:196-204, 1977) against 40 clinically isolated strains. Mean reciprocal bactericidal titers were measured 1 and 6 h after administration. After 1 and 6 h the median SBAs for imipenem and meropenem, were 409 and 34.9 and 97.9 and 5.8, respectively, against Staphylococcus aureus, 19.9 and 4.4 and 19.4 and 4.8, respectively, against Pseudomonas aeruginosa, 34.3 and 2.2 and 232 and 15.5, respectively, against Enterobacter cloacae, and 13.4 and 2.25 and 90.7 and 7.9, respectively, against Proteus mirabilis. Both drugs had rather short biological elimination half-lives and a predominantly renal route of elimination. Both carbapenems revealed high SBAs against clinically important pathogens at 1 h; meropenem had a higher SBA against E. cloacae and P. mirabilis, and the SBA of imipenem against S. aureus was greater than the SBA of meropenem.

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