Josef Rosenberg | University of West Bohemia (original) (raw)

Papers by Josef Rosenberg

Česká urologie, 2003

Vyšetření uretrálního tlakového profilu bylo navrženo již před více než 30 lety. Přes četné limit... more Vyšetření uretrálního tlakového profilu bylo navrženo již před více než 30 lety. Přes četné limity je zejména gynekology dosud využíváno jako standardní metoda k hodnocení funkčního stavu uretrálního uzavíracího mechanismu. Autoři vyhodnotili metodu statické profilometrie, i když závěry lze rozšířit na všechny postupy, používající perfuzní metodu měření.

Applied and Computational Mechanics, 2022

The presented paper is devoted to studying the dynein molecular motor and its stochastic descript... more The presented paper is devoted to studying the dynein molecular motor and its stochastic description. The model aims to obtain good results comparable to literature sources qualitatively. We choose the Hoover-Holian oscillator to describe the dynein behaviour of each of its legs. It can catch the stochastic movement produced by Brownian motion and can be modified to simulate a load.

Journal of Applied Mathematics and Mechanics, 1985

Allgemeine Variationsprinzipien in den Evolutionsaufgaben der Kontinuumsmechanik und der diskrete... more Allgemeine Variationsprinzipien in den Evolutionsaufgaben der Kontinuumsmechanik und der diskreten mechanischen Systeme In der Arbeit wird eine allgemeine Methode zur Formulierung von Variationsprinzipien fur Evolutionsrandwertprobleme vorgestellt. Diese Methode geht aus der Wahl der Bilinearform als inneres Produkt hervor. Neben der klassischen Bilinearform wird auch die konvolutorische Form verwendet, deren Einsatz ee erlaubt, Variationsprinzipien zu formulieren, die auch die Anfangsbedingungen enthalten. Die dargelegte Methode wird auf die isotherme Stromung viskoser Fliissigkeiten und auf die Mechanik diskreter mechanischer Systeme angewendet. The study contains a general method of the variation principle formulation for evolutional boundary problems. !Phis method proceeds from the choice of a bilinear form as a scalar product. The bilinear convolutional form was also wed besides of the classical integral bilinear one. Its use admits a variation principle formulation containing original conditions as well. The given method is applied to ietthermal flow of a vimous liquid and to the mechanics of diacrete mechanical eystems. B pa6o~e npktsegeI1 0614uii MeToH (POPMYJIHPOBKH 3~c~p e~a n b~b 1~ sapuaquoHnbix n p~~s H n o~ g m ~B O J I-mUMoHHbix KpaeBMx aagas. TOT MeToa MCXOHMT 133 sb160pa 6una~einoB (POPM~I nan cKanrrpHoro npom-seneHun. IXpuMemeTcH, Hapsny c nnaccmecnoB mrrerpanbHoB 6ununeB~oi (Poplrrot, TaKme 6 m~n e t~a~ KoHBmmTopHaH (PopMa. Ee npmeHeme ~O~B O J I H~T (PopMynuposam sapnaquoHHHe npmxqunbi, BHJIIO-qamuIMe Taxme Hasammie Y C~O R E I H. FIpaBeResebrt4 MeTOH npHnaraeTcH K moTepMwecKoMy TeqeHum B H~K O C~ MIHKOCTH M n MexaHune AacnpeTHbix MexaHmecnux cucTeM.

Mechanism and Machine Theory, 1976

Eingegangen am 12. Dezember 1975 Zusammenfassung Die vorliegende Ver6ffentlichung iiber die mathe... more Eingegangen am 12. Dezember 1975 Zusammenfassung Die vorliegende Ver6ffentlichung iiber die mathematische Untersuchung der Beriihrverh~iltnisse h6herer kinematischer Paare stelt eine 0bersicht der Arbeiten des Verfassers auf diesem Gebiet dar. In diesem Aufsatz werden als besondere Anwendungs-beispiele die Kegel-und Hypoidriider betrachtet, bei denen die Eingriffsbedingungen im Berechnungspunkt von Interesse sind. Im Gegensatz zu bereits bekannten Arbeiten werden hierbei die Kontaktbedingungen auf eine bestimmte Bewegungsphase bezogen. Die allgemeine Form der verwendeten Algorithmen I~.Bt die Untersuchung der Lokaleigenschaften auch fiir die deformierte Lage der kinematischen Kette zu, um beispielsweise eine Lasteinwirkung zu beriJcksichtigen.

Intersticiální buňky Cajalova typu (IC-LC) hrají důležitou roli při fyziologické i patologické fu... more Intersticiální buňky Cajalova typu (IC-LC) hrají důležitou roli při fyziologické i patologické funkci močového měchýře. Aautory vyvinutý relativně jednoduchý model sestává z pěti nelineárních obyčejných diferenciálních rovnic (ODE). Jeho přesnost byla ověřena srovnáním s publikovanými experimentálními výsledky. Hlubší analýza tohoto modelu ukázala existenci více stabilních a tzv. skrytých atraktorů, které mohou významně ovlivňovat chování celého měchýře. Jako výhodné se ukázalo využití metody, založené na perpetuálních bodech. V příspěvku je stručně uvedena definice těchto bodů. Ač tato metoda není dosud plně dokázána, dovoluje určit výše uvedené atraktory. Cílem je prokázat aplikaci této metody na uvedeném 5D systému. Toto je demonstrováno na několika příkladech.Cajal-like interstitial cells (IC-LC) play important role in both physiological and pathological function of the bladder. The authors developed relative simple mathematical model consisting of five nonlinear ODEs. The model...

Západočeská univerzita v Plzni, 2019

Computer Methods in Applied Mechanics and Engineering, 1992

Abstract A variational inequality formulation in strain space is derived for certain problems of ... more Abstract A variational inequality formulation in strain space is derived for certain problems of flow theory elasto-plastic deformation with hardening. An algorithm is given for implementing a finite element approximation to the variational inequality formulation.

The theory of growth and remodeling is applied to the 1D continuum. This can be mentioned e.g. as... more The theory of growth and remodeling is applied to the 1D continuum. This can be mentioned e.g. as a model of the muscle fibre or piezo-electric stack. Hyperelastic material described by free energy potential suggested by Fung is used whereas the change of stiffness is taken into account. Corresponding equations define the dynamical system with two degrees of freedom. Its stability and the properties of bifurcations are studied using multiple-scale method. There are shown the conditions under which the degenerated Hopf’s bifurcation is occuring.

Applied and Computational Mechanics, 2013

The complex model of the lower part of the urinary tract is introduced. It consists of the detrus... more The complex model of the lower part of the urinary tract is introduced. It consists of the detrusor smooth muscle cell model and the detailed 1D model of the urethra flow. The nerve control is taken into account. In future this model will allow to simulate the influence of different drugs and mechanical obstructions in the bladder neck and urethra. A general muscle model involving the calcium dynamics in the smooth muscle cell and the growth and remodelling theory will be shortly introduced. For the modelling calcium dynamics the approach of Koenigsberger published in Biophysical Journal (Koenigsberger, M., Sauser, R., Seppey, D., Beny, J.-L., Meister, J.-J., Calcium dynamics and vosomotion in arteries subject to isometric, isobaric and isotonic conditions, Biophysical Journal 95 (2008) 2 728–2 738.) was adopted. The model includes the ATP consumption calculation according to Hai et al. (Hai, C. M., Murphy, R. A., Adenosine 5’-triphosphate consumption by smooth muscle as predicted b...

Muscle fibre contraction is a complex thermomechanical process. The change in muscle fibre length... more Muscle fibre contraction is a complex thermomechanical process. The change in muscle fibre length (isotonic contraction) and tension (isometric contraction) may be regarded as muscle fibre growth (change in length) and remodelling (change in stiffness). In this study a general mathematical model based on the growth and remodelling theory and the theory of irreversible thermodynamics is proposed. The isometric contraction of muscle fibre is treated as an isothermal process. The relevance of chemical agents diffusion is also discussed.

We propose a new numerical scheme based on the finite volumes to simulate the urethra flow based ... more We propose a new numerical scheme based on the finite volumes to simulate the urethra flow based on hyperbolic balance law. Our approach is based on the Riemann solver designed for the augmented quasilinear homogeneous formulation. The scheme has general semidiscrete wave–propagation form and can be extended to arbitrary high order accuracy. The first goal is to construct the scheme, which is well balanced, i.e. maintains not only some special steady states but all steady states which can occur. The second goal is to use this scheme as the component of the complex model of the urinary tract including chemical reactions and contraction of the bladder.

There exist different formulations of the irreversible thermodynamics. Depending on the distance ... more There exist different formulations of the irreversible thermodynamics. Depending on the distance from the equilibrium state and on the characteristic time the main theories are the classical theory (CIT), the thermodynamics with internal variables (IVT) and the extended theory (EIT). Sometimes it is not easy to choose the proper theory and to use it efficiently with respect to applied problems considering different fields of interest. Especially EIT is explained mainly for very special choice of the dissipative fluxes under specific presumptions. The paper tries to formulate EIT and IVT in a simple, unified but general enough form. The basic presumptions for EIT are shown and discussed, further a possible generalization is proposed. The formulation allows the integration of IVT and EIT even for the mixture of chemically interacting components and diffusion. The application of the formulation is demonstrated on an example.

Frontiers in Physiology

Metabolic syndrome is associated with hypercholesterolemia, cardiac remodeling, and increased sus... more Metabolic syndrome is associated with hypercholesterolemia, cardiac remodeling, and increased susceptibility to ventricular arrhythmias. Effects of diet-induced hypercholesterolemia on susceptibility to torsades de pointes arrhythmias (TdP) together with potential indicators of arrhythmic risk were investigated in three experimental groups of Carlsson’s rabbit model: (1) young rabbits (YC, young control, age 12–16 weeks), older rabbits (AC, adult control, age 20–24 weeks), and older age-matched cholesterol-fed rabbits (CH, cholesterol, age 20–24 weeks). TdP was induced by α-adrenergic stimulation by methoxamine and IKr block in 83% of YC rabbits, 18% of AC rabbits, and 21% of CH rabbits. High incidence of TdP was associated with high incidence of single (SEB) and multiple ectopic beats (MEB), but the QTc prolongation and short-term variability (STV) were similar in all three groups. In TdP-susceptible rabbits, STV was significantly higher compared with arrhythmia-free rabbits but no...

Higher Education Management and Policy, 2002

Experimental biology and medicine (Maywood, N.J.), Oct 20, 2016

Although patients with lower urinary tract symptoms constitute a large and still growing populati... more Although patients with lower urinary tract symptoms constitute a large and still growing population, understanding of bladder detrusor muscle physiology remains limited. Understanding the interactions between the detrusor smooth muscle cells and other bladder cell types (e.g. interstitial cells, IC) that may significantly contribute to coordinating and modulating detrusor contractions represents a considerable challenge. Computer modeling could help to elucidate some properties that are difficult to address experimentally; therefore, we developed in silico models of detrusor smooth muscle cell and interstitial cells, coupled through gap junctions. The models include all of the major ion conductances and transporters described in smooth muscle cell and interstitial cells in the literature. The model of normal detrusor muscle (smooth muscle cell and interstitial cells coupled through gap junctions) completely reproduced the experimental results obtained with detrusor strips in the pre...