530 research outputs found
Kinetics and the Theoretical Aspects of Drug Release from PLA/HAp Thin Films
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The theory of dissolution kinetics of gentamicin from polylactic acid-hydroxyapatite thin film composites is spotlighted with the combination of diffusion and polymer degradation modeling. The use of various mathematical models, characterizing diffusion, dissolution or/and erosion prevalence as well as a mix of dissolution-diffusion rate processes were employed in order to compare theory with experimental data. A number of factors influence the release kinetics of gentamicin from medical drug release systems and devices. It is difficult to have a single mathematical model that takes all these factors into account. It is shown that the degradation of the polymer matrix plays the biggest role in the release kinetics of polymer-ceramics thin film composites. It was also observed that multistage drug release form these devices depends also on the degradation kinetics of the polymer matrix. The effect of pH and device sizes were not studied but could also be of interest in future studies
DEFICIENCY OF THE FIFTH COMPONENT OF COMPLEMENT IN MICE WITH AN INHERITED COMPLEMENT DEFECT
The inherited complement deficiency of certain inbred strains of mice was shown to be due to an isolated lack of the fifth component of complement. The protein MuB1 (or hc'), which is present in normal mouse serum but absent from the serum of complement-deficient mice, was shown to be immunochemically related to the fifth component of human complement (C'5). C'5 hemolytic activity was specifically inhibited in human serum by mouse anti-MuB1 and in normal mouse serum by mouse antiserum to human C'5. Highly purified human C'5 reconstituted the hemolytic activity of complement-deficient mouse serum. It was, therefore, concluded that he', or MuB1, constitutes the murine analogue of the fifth component of human complement. The MuB1 concentration in normal mouse serum was found to be subject to a sex-related variation. By quantitative precipitin analysis it was demonstrated that serum from male mice contains twice as much MuB1 as that of female mice. This difference in C'5 concentration was also detected by hemolytic assay. In addition, C'6 and C'7 were also found to be subject to sex-related variations
THE EIGHTH COMPONENT OF HUMAN COMPLEMENT (C8): ISOLATION, CHARACTERIZATION, AND HEMOLYTIC EFFICIENCY
An elementary approach to rigorous approximation of invariant measures
We describe a framework in which is possible to develop and implement
algorithms for the approximation of invariant measures of dynamical systems
with a given bound on the error of the approximation.
Our approach is based on a general statement on the approximation of fixed
points for operators between normed vector spaces, allowing an explicit
estimation of the error.
We show the flexibility of our approach by applying it to piecewise expanding
maps and to maps with indifferent fixed points. We show how the required
estimations can be implemented to compute invariant densities up to a given
error in the or distance. We also show how to use this to
compute an estimation with certified error for the entropy of those systems.
We show how several related computational and numerical issues can be solved
to obtain working implementations, and experimental results on some one
dimensional maps.Comment: 27 pages, 10 figures. Main changes: added a new section in which we
apply our method to Manneville-Pomeau map
Comparison of LHC collimator beam-based alignment to BPM-interpolated centers
The beam centers at the Large Hadron Collider collimators are determined by beam-basedalignment, where both jaws of a collimator are moved in separately until a loss spike isdetected on a Beam Loss Monitor downstream. Orbit drifts of more than a few hundredmicrometers cannot be tolerated, as they would compromise the performance of thecollimation system. Beam Position Monitors (BPMs) are installed at various locations aroundthe LHC ring, and a linear interpolation of the orbit can be obtained at the collimatorpositions. In this paper, the results obtained from beam-based alignment are compared withthe orbit interpolated from the BPM data throughout the 2011 and 2012 LHC proton runs.Louisiana State University (LSU),U.S. Department of Energy, Office of Science,COSYLAB,DIMTEL,Muons, Inc.peer-reviewe
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