Purchase individual online access for 1 year to this journal.
Price: EUR 90.00
Impact Factor 2019: 0.933
Biorheology is an international interdisciplinary journal that publishes research on the deformation and flow properties of biological systems or materials. It is the aim of the editors and publishers of
Biorheology to bring together contributions from those working in various fields of biorheological research from all over the world. A diverse editorial board with broad international representation provides guidance and expertise in wide-ranging applications of rheological methods to biological systems and materials.
The aim of biorheological research is to determine and characterize the dynamics of physiological processes at all levels of organization. Manuscripts should report original theoretical and/or experimental research promoting the scientific and technological advances in a broad field that ranges from the rheology of macromolecules and macromolecular arrays to cell, tissue and organ rheology. In all these areas, the interrelationships of rheological properties of the systems or materials investigated and their structural and functional aspects are stressed.
The scope of papers solicited by
Biorheology extends to systems at different levels of organization that have never been studied before, or, if studied previously, have either never been analyzed in terms of their rheological properties or have not been studied from the point of view of the rheological matching between their structural and functional properties. This biorheological approach applies in particular to molecular studies where changes of physical properties and conformation are investigated without reference to how the process actually takes place, how the forces generated are matched to the properties of the structures and environment concerned, proper time scales, or what structures or strength of structures are required.
Biorheology invites papers in which such 'molecular biorheological' aspects, whether in animal or plant systems, are examined and discussed. While we emphasize the biorheology of physiological function in organs and systems, the biorheology of disease is of equal interest. Biorheological analyses of pathological processes and their clinical implications are encouraged, including basic clinical research on hemodynamics and hemorheology.
In keeping with the rapidly developing fields of mechanobiology and regenerative medicine,
Biorheology aims to include studies of the rheological aspects of these fields by focusing on the dynamics of mechanical stress formation and the response of biological materials at the molecular and cellular level resulting from fluid-solid interactions. With increasing focus on new applications of nanotechnology to biological systems, rheological studies of the behavior of biological materials in therapeutic or diagnostic medical devices operating at the micro and nano scales are most welcome.
Abstract: This paper undertakes a parallel analysis of the gelation mechanisms, structure and rheological properties of gelatin and collagen gels. Although the molecular compositions of collagen and gelatin are almost identical, gelation proceeds from distinct mechanisms and leads to different types of molecular assemblies. First are presented the properties of the solutions, based on their structural and rheological characterization; then the mechanisms of gelation in the networks, observed by Transmission Electron Microscopy, of three types of gels: gelatin gels, Type I collagen gels and gels made of cuticle collagen extracted from annelid worms. The rheological investigation of the sol-gel transition of…gelatin is described within the context of the theories of percolation and scaling laws. Different experimental approaches to the kinetics of gelation are presented, combining dynamic light scattering and rheology in respect to gelatin gels.
Keywords: Collagen, gelatin, gels, rheology, electron microscopy
vol. 30, no. 3-4, pp. 191-205, 1993
Abstract: Rheological studies on the gelation of casein micelles using rennet have been performed in relation to cheese making. The influence of calcium concentration on the time course of storage and loss modulus was investigated using rheological measurements. Observed gelation curves at 30°C were well approximated by first-order reaction kinetics except for the very short time after gelation occurred. The saturated modulus decreased with decreasing calcium ion concentration in the range from 4.5 to 9 mM. The rate constant of gelation, Kg decreased linearly with decreasing calcium ion concentration. A minimum amount of calcium was needed for gelation to occur.…Kg was inversely proportional to the latent time, tL . The value of the product of Kg and tL for the casein micelle gels containing various calcium concentrations was 0.4.
Keywords: Casein micelle, gelation, rennet, viscoelasticity, calcium ion
vol. 30, no. 3-4, pp. 207-216, 1993
Abstract: Small deformation oscillatory shear measurements have enabled a distinction to be made between so-called “strong” and “weak” gels, in particular those formed from biologically significant polysaccharides. At small enough strains, both systems give essentially the same mechanical spectrum, with G ′ > G ″ , and with both moduli largely independent of frequency. However, the deformation dependence of the two classes of materials is very different. Strong gels are essentially strain independent (linearly viscoelastic) for strains of greater than about 0.25, whereas weak gels show such a response only for strains of…less than about 0.05. At large deformations strong gels will rupture and fail, and will never “heal” without melting and resetting. Conversely, weak gels will recover and can flow without fracture, giving a power law response, with an exponent approaching -1, so-called “yield stress” behavior. The rheological properties of a strong gel, agarose, derived from the Rhodophyceae (marine algae) and a weak gel xanthan, an exocellular slime exuded by bacteria of the genus Xanthomonas , are measured in vitro , and related to in vivo requirements.
Abstract: The viscoelastic behavior of arterial elastin in aqueous solutions of polar solutes has been studied to establish both its range of behavior and the mechanisms by which the behavior is altered by the solutes. We were particularly interested in whether a solute interacted directly with the elastin or whether it acted only indirectly to reduce the activity of water. The behavior of elastin in solutions of glucose, NaCl ammonium sulphate, and in low concentrations of ethylene glycol was similar to that of elastin that had been directly dehydrated or indirectly dehydrated using osmotic agents such as dextran or polyethylene glycol.…This similarity suggests that these solutes interact with elastin only indirectly. Thiocyanate and high concentrations of dimethyl sulfoxide and ethylene glycol appeared to interact directly with the elastin, altering both the swelling and the viscoelastic behavior of the network.
Abstract: Viscoelastic parameters for mixtures of gelatin and methy1cellulose were measured as a function of temperature, in order to study the gel-sol transition of the system in which biopolymers forming thermosetting and thermo-melting gels coexist. At higher temperatures than 45°C, the gel network is mainly formed by methylcellulose while at lower temperatures around 5°C, it is mainly formed by gelatin. At higher temperatures than 45°C, gelatin inhibits the gelation of methylcellulose. A small amount of methylcellulose helps gelatin to form a network at lower temperatures. However, excessive amounts of methylcellulose inhibit the growth of network structure. Therefore, this mixture forms a…phase separated gel at higher temperatures while it is not completely phase separated at lower temperatures, probably by some interaction between non-substituted hydroxyl groups in methylcellulose with carboxylic groups in gelatin.
Abstract: For transient shear stress responses at moderate shear rates, predictions of a Non-Linear Maxwell model , in which the viscosity coefficient is assumed to depend on the instantaneous structural state of the material, are compared to measurements on normal blood (McMillan et al ., 1986). This is carried out on a modified viscometer which incorporates a dynamic balance torque monitoring, in order to eliminate apparatus inertia effects. Satisfactory agreement is obtained with model variables closely related to the structure kinetics.
Abstract: We re-examined the measurement of the mass flow ratio at model bifurcations as a function of the inlet Reynolds number, which has been used to study the role of arterial bifurcation in distal blood supply. However, this relationship was found not to be applicable to investigations of blood circulation, because the measured mass flow ratio is strongly dependent on the resistance downstream of the bifurcation, and therefore is specific to the experimental set-up. An alternative approach for studying the role of arterial bifurcation is presented, in which the flow division ratio is used as a parameter.
Abstract: Although a decrease in the deformability of red blood cells (RBCs) has been suspected in Heinz body-forming hemolytic anemia, it remains uncertain whether the formation of Heinz bodies themselves impairs RBC deformability or not. To elucidate this question, we used RBCs treated with phenylhydrazine and RBCs from patients with unstable hemoglobin (Hb) disease (Hb Yokohama) to investigate the effect of Heinz body formation on deformability in terms of RBC filterability through nickel mesh and viscosity of the RBC suspension. The phenylhydrazine-treated RBCs exhibited a marked decrease in deformability in a dose-dependent manner. The Heinz body-forming RBCs from the patients also…showed a marked decrease in deformability. Thus we confirmed that Heinz body formation impairs RBC de formability. Further, both phenylhydrazine-treated RBCs and RBCs from the patient showed a degradation of spectrin without any cross-linking of membrane proteins, thereby suggesting that the impaired deformability is associated with the oxidative degradation of the cytoskeletal framework. In summary, this study supports the conclusion that RBC deformability is impaired by the presence of Heinz bodies as well as the related oxidative damage involved in their formation.
Abstract: Flow characteristics are examined in two lateral model aneurysms by means of numerical simulation. The study concentrates on basic flow and stress patterns in a rigid wall and in a distensible wall aneurysm. The numerical solution of the governing Navier-Stokes equations describing incompressible, pulsatile, three-dimensional non-Newtonian flow is accomplished with the use of a finite element method together with a pressure correction technique. The inflow into the aneurysm is seen to arise from the downstream lip of the orifice and to be directed backward to the center. Backflow to the parent vessel takes place along the walls of the aneurysm.…The intra-aneurysmal flow is found to be low compared with the flow velocity in the parent vessel, and even stagnation of flow occurs in the dome of the aneurysm. With a distensible wall, the basic flow characteristics are changed during systolic flow. The intra-aneurysmal secondary flow increases significantly. The increase and decrease of the flow velocity at the downstream lip reflect the expansion and contraction of the aneurysm wall where the maximal wall displacement during systolic acceleration is about 6% of the aneurysm diameter.