Geometric Factor as the Characteristics of the Three-Dimensional Process of Volume Changes of Heavy Soils

During simulation of a water regime of heavy soils, it is necessary to know the isotropy parameters of any volume changes. Volume changes appear in both vertical and horizontal directions. In vertical directions, they appear as a topsoil movement, and in horizontal directions as the formation of a crack network. The ratio between horizontal and vertical change is described using the geometric factor, rs. In the present paper, the distribution of volume changes to horizontal and vertical components is characterized by the geometric factor, in selected soil profiles, in the East Slovakian Lowland. In this work the effect of soil texture on the value of the geometric factor and thus, on the distribution of volume changes to vertical and horizontal components was studied. Within the hypothesis, the greatest influence of the clay soil component was shown by the geometric factor value. New information is obtained on the basis of field and laboratory measurements. Results will be used as inputs for numerical simulation of a water regime for heavy soils in the East Slovakian Lowland

The effect of solution pH on the structural stability of magnetoferritin

The structural stability of magnetoferritin, a synthetic analogue of ferritin, at various pH levels is assessed here. The structural and electrical properties of the complexes were determined by small-angle X-ray scattering (SAXS), dynamic light scattering (DLS) and zeta potential measurements. At pH 3 − 6 a reduction of electrostatic repulsion on the suspended colloids resulted in aggregation and sedimentation of magnetoferritin. At neutral to slightly alkaline conditions (pH 7–9) the magnetoferritin structure was stable for lower iron loadings. Higher solution pH 10–12 induced destabilization of the protein structure and dissociation of subunits. Increasing the loading factor in the MFer complex leads to decrease of the stability versus pH changes

Interaction of Magnetic Nanoparticles with Lyotropic Liquid Crystal Studied by AFM

In this work the interaction of lysozyme fibrils with magnetic particles has been studied by atomic force microscopy. The experiments were carried out for a better understanding of the binding process of such complex soft matter systems. The obtained results show that interaction between lysozyme fibrils and magnetic particles starts immediately after mixing them together. Moreover, the samples remain stable in duration of several days after preparation

The Impact of Redox, Hydrolysis and Dehydration Chemistry on the Structural and Magnetic Properties of Magnetoferritin Prepared in Variable Thermal Conditions

Ferritin, a spherically shaped protein complex, is responsible for iron storage in bacteria, plants, animals, and humans. Various ferritin iron core compositions in organisms are associated with specific living requirements, health state, and different biochemical roles of ferritin isomers. Magnetoferritin, a synthetic ferritin derivative, serves as an artificial model system of unusual iron phase structures found in humans. We present the results of a complex structural study of magnetoferritins prepared by controlled in vitro synthesis. Using various complementary methods, it was observed that manipulation of the synthesis technology can improve the physicochemical parameters of the system, which is useful in applications. Thus, a higher synthesis temperature leads to an increase in magnetization due to the formation of the magnetite phase. An increase in the iron loading factor has a more pronounced impact on the protein shell structure in comparison with the pH of the aqueous medium. On the other hand, a higher loading factor at physiological temperature enhances the formation of an amorphous phase instead of magnetite crystallization. It was confirmed that the iron-overloading effect alone (observed during pathological events) cannot contribute to the formation of magnetite

Disruption of amyloid aggregates by artificial ferritins

Presence of protein amyloid aggregates is associated with many neurodegenerative disorders, such as Alzheimer’s disease etc. The effect of magnetoferritin and reconstructed ferritin on the structure of lysozyme amyloid aggregates was studied using small-angle X-ray scattering, atomic force microscopy and thioflavin T fluorescence measurements. It has been shown that both magnetoferritin and reconstructed ferritin molecules affect the size, structure and amount of the amyloid fibrils. We assume that the anti-amyloid effect of magnetoferritin and reconstructed ferritin is due to the presence of iron in solutions but is not associated with the magnetic character of the iron oxide phases, i.e. magnetite/maghemite for magnetoferritin and ferrihydrite for ferritin