Reduction of Non-Linear Absorption in Li2B4O7 by Controlling Temperature and Repetition Rate

2008 ◽  
Author(s):  
Masakuni Takahashi ◽  
Ichiro Sekine ◽  
Marilou Cadatal ◽  
Nobuhiko Sarukura ◽  
Peter F. Moulton ◽  
...  
Keyword(s):  
Repetition Rate ◽  
Linear Absorption ◽  
Non Linear

Selection and self-locking of modes in He-Ne lasers with non-linear absorption

1968 ◽  
Vol 4 (5) ◽  
pp. 339-339 ◽  
Author(s):  
V. Chebotayev ◽  
I. Beterov ◽  
V. Lisitsyn
Keyword(s):  
Linear Absorption ◽  
Non Linear

scholarly journals A preclinical study to model taurine pharmokinetics in the undernourished rat

2018 ◽  
Vol 119 (7) ◽  
pp. 826-835 ◽  
Author(s):  
Ana Catalán-Latorre ◽  
Amparo Nácher ◽  
Virginia Merino ◽  
Octavio Díez ◽  
Matilde Merino Sanjuán
Keyword(s):  
Preclinical Study ◽  
Population Pharmacokinetic ◽  
Process Data ◽  
Internal Organs ◽  
Linear Absorption ◽  
First Order Kinetics ◽  
Protein Energy ◽  
Non Linear ◽  
Linear Elimination ◽  
Passive Absorption

AbstractMalnutrition is a common feature of chronic and acute diseases, often associated with a poor prognosis, including worsening of clinical outcome, owing, among other factors, to dysfunction of the most internal organs and systems affecting the absorption, metabolism and elimination of drugs and nutrients. Taurine is involved in numerous biological processes and is required in increased amounts in response to pathological conditions. The aim of this study was to describe the behaviour of taurine in well-nourished (WN) rats and to analyse the influence of protein–energy undernutrition on the pharmacokinetic (PK) parameters of taurine, using a PK model. Wistar rats were randomly distributed into two groups, WN and undernourished (UN), and taurine was administered intravenously or orally at different doses: 1, 10 and 100 mg. Population pharmacokinetic modelling of plasma levels was performed using the NONMEM 7.2 program. Several distribution and absorption models were explored in combination with dose and/or time covariate effects. Covariates such as nutritional status, serum albumin, body weight and score of undernutrition were used. A two-compartment population pharmacokinetic model with zero-order endogenous formation, passive absorption, first-order kinetics distribution and non-linear elimination with parallel Michaelis–Menten excretion and reabsorption processes best described taurine pharmacokinetics. Undernutrition acted as a covariate reducing theVmaxof the active elimination process. Data analysis showed linear absorption and distribution, and non-linear elimination processes for taurine. Elimination of taurine was reduced in UN animals, suggesting that the reabsorption process via the secretion transporter was modified in that group.

scholarly journals A theoretical and experimental study of non-linear absorption properties of substituted 2,5-di-(phenylethynyl)thiophenes and structurally related compounds

2009 ◽  
Vol 107 (7) ◽  
pp. 629-641 ◽  
Author(s):  
Per Lind ◽  
Marcus Carlsson ◽  
Bertil Eliasson ◽  
Eirik Glimsdal ◽  
Mikael Lindgren ◽  
...  
Keyword(s):  
Experimental Study ◽  
Absorption Properties ◽  
Linear Absorption ◽  
Non Linear ◽  
Related Compounds

Surface and kinetic effects in gas chromatographic studies of polystyrene

1976 ◽  
Vol 54 (22) ◽  
pp. 3496-3507 ◽  
Author(s):  
Gregory J. Courval ◽  
Derek G. Gray
Keyword(s):  
Sample Size ◽  
Flow Rate ◽  
Retention Volume ◽  
Rate Dependence ◽  
Retention Data ◽  
Scanning Electron Micrographs ◽  
Linear Absorption ◽  
Solvent Interactions ◽  
Non Linear ◽  
Polymer Solvent

Considerable variation in the measurement of polymer–solvent interactions using gc retention data may occur due to kinetic factors, surface excess concentrations of probe vapour, and non-linear partition isotherms. The kinetic factors, which appear as a flow rate dependence of the retention volume, are analysed in terms of a previously reported theoretical model for retention on polymeric stationary phases passing through the glass transition. The predicted linear extrapolations to zero flow rate are obtained for the retention of n-tetradecane on polystyrene. The variation of this flow rate dependence with temperature and with the thickness of the stationary phase are also in qualitative agreement with the theory. A simplified model for the effect of loading on the retention diagram is presented. Non-linear absorption and bulk sorption isotherms result in a dependence of retention volume on sample size, necessitating an extrapolation of the measured retention volumes to zero peak height. The temperature variation of the flow rate dependence, the effect of loading, and the effect of sample size on retention volume are all further complicated by uneven distribution of polymer on support. From scanning electron micrographs of the beads it is evident that 'beading up' of the polystyrene on the glass surface may occur at low loadings, resulting in a non-uniform coating with large areas of the beads uncoated. It is concluded that in order to obtain reliable data on polymer–solvent interactions using gas chromatography, all of the above-mentioned factors must be considered.

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