This study deals with the application of the previously developed immobilized and perfused isolated hepatocytes as a cellular system for the study of representative phase 1 and phase II of biotransformation reactions. To illustrate phase I reactions, aminopyrine (0.17-4.25 mmol/1) and hexobarbital (0.2 mmol/1) were selected. For phase II reactions, glutathione transferase activity was evaluated by using l-chloro-2,4-dinitrobenzene (CDNB) as a substrate (0.125-2.0 mmol/1). Formaldehyde, that was formed from aminopyrine, increased steadily in the perfusion medium with time. The perfused hepatocytes eliminated hexobarbital at a much higher rate than the hepatocytes in suspension. At several time points the amount of CDNB-glutathione conjugate formed per one million hepatocytes in the bioreactor was almost twice the amount formed by the hepatocytes in suspension. The present data illustrate the successful application of the hepatocyte bioreactor in phase I and phase II of xenobiotic metabolism and indicate that the cells were metabolically more active than the cells in suspension.
It has been shown that, in addition to conventional contact electrode techniques, optical methods using fluorescent dyes can be successfully used for cardiac signal measurement. In this review, the physical and technical fundamentals of the method are described, as well as the properties of the most common systems for measuring action potentials and intracellular calcium concentration. Special attention is paid to summarizing limitations and trends in developing this method., M. Ronzhina, ... [et al.]., and Obsahuje seznam literatury
This work presents new application of the random field theory in medical imaging. Results from both integral geometry and random field theory can be used to detect locations with significantly increased radiotracer uptake in images from positron emission tomography (PET). The assumptions needed to use these results are verified on a set of real and simulated phantom images. The proposed method of detecting activation (locations with increased radiotracer concentration) is used to quantify the quality of simulated PET images. Dependence of the quality on the injection dose (amount of applied radiotracer) and patient's body parameters is estimated. It is used to derive curves of constant quality determining the injection dose needed to achieve desired quality of the resulting images. The curves are compared with the formula currently used in medical practice.
The aim of this article is to inform reader about the development steps which are used during the development of a critical control algorithm in aerospace industry. An article describes the motivation for use of automatic code generators for the development of critical control applications. A V-cycle model based design is introduced and its advantages and development practices that lead from design of a MATLAB/Simulink models to a real target application are depicted. and Obsahuje seznam literatury
SSCP (single-strand conformation polymorphism) analyses of ubiquitin genes were used to investigate evolutionary relationships within the subgenus Orinocarabus of the genus Carabus. After SSCP electrophoresis of PCR-amplified ubiquitin copies, population-specific band patterns were obtained. Ubiquitin-SSCP-analyses of the six central European Orinocarabus species, including three subspecies and thirteen populations, resulted in a dendrogram that differed from that based on morphology. Phylogenetic analysis of mitochondrial DNA (mtDNA) did not support the SSCP dendrogram, but was in good accordance with the taxonomy based on morphological characters. The reason for the discrepancies seems to be evolutionary conservation of the ubiquitin genes. The time that elapsed since the evolution of the closely related Orinocarabus species is too short for concerted evolution of the ubiquitin genes.
The aim of this paper is an investigation of damping properties of polyurethane materials that were produced from polyurethane foam granules. There were used polyurethane materials with different thickness and inertial masses. After measurements of damping vibration, the polyurethane samples were compared and recommended in reference to their damping properties. and Tématem tohoto příspěvku je vyšetření tlumících vlastností polyuretanových materiálů vyrobených z polyuretanových pěnových granulí. Byly použity polyuretanové materiály s různými tloušťkami a setrvačnými zátěžemi. Po provedení měření útlumů vibrací polyuretanových vzorků byly jednotlivé vzorky porovnány a doporučeny z hlediska jejich tlumících vlastností.
A synthesis of recent development of regime-switching models based on aggregation operators is presented. It comprises procedures for model specification dans identification, parameter estimation and model adequacy testing. Constructions of models for real life data from hydrology and finance are presented.
Authors propose a beneficial methodology for hydrological planning in their study. Prospective evaluations of the basins' net capacity can be done using the technique presented. The HEC-HMS (Hydrologic Modelling System) software can be used to estimate in a basin, the sediment emitted. For a certain precipitation, this methodology allows estimating, within a certain range, the gradual blockage of a reservoir, and even a projected date for total blockage. This has some applications to adopt corrective measures that prevent or delay the planned blockage deadlines. The model is of the semi-distributed type, estimating the generation and emission of sediments by sub-basins. The integration of different return periods in HEC-HMS with a semi-distributed model by sub-basins and the application of a mathematical model are the differentiating element of this research. The novelty of this work is to allow prognosing the reservoir sedimentation rate of basins in a local and regional scale with a medium and large temporary framework. The developed methodology allows public institutions to take decisions concerning hydrological planning. It has been applied to the case of "Charco Redondo" reservoir, in Cádiz, Andalusia, in southern Spain. Applying the methodology to this case, an average soil degradation of the reservoir basin has been estimated. Therefore, it is verified that in 50 years the reservoir is expected to lose 8.4% of its capacity.