Transport through structures such as pores and ion channels is ubiquitous in nature. It has been intensively studied recent years. Especially biological cells, the movement of molecules channel systems plays an essential role controlling almost every physiological function living organisms. The subject our study kinetics spherical particles passing a conical pore restricted by absorbing reflecting boundaries from wider to narrower end vice versa. We properties diffusion particle size with...

Simulations of the Brownian dynamics diffusing particles in complex environments provide important information about characteristics medium and properties biological processes. Notable examples include diffusion ions macromolecular solutes through channels varying cross-section, such as pores membranes, living tissues, zeolites, carbon nanotubes, synthetic porous materials. In these systems, observed can exhibit anomalous behavior characterized by a nonlinear increase mean squared...

Adsorption of fibrinogen, modeled as a linear chain touching beads various sizes, was theoretically studied using the random sequential adsorption (RSA) model. The process assumed to consist two steps: (i) formation an irreversibly bound fibrinogen monolayer under side-on orientation, which is independent bulk protein concentration and (ii) reversibly bound, end-on monolayer, whose coverage dependent on concentration. Calculation based RSA model showed that maximum surface (reversible)...

Irreversible side-on adsorption of fibrinogen, modeled as a linear chain touching beads various size, was studied theoretically using the random sequential (RSA) model. Numerical simulation Monte Carlo type enabled one to determine dependence surface blocking function (available function) on protein coverage. These numerical results were interpolated analytical functions based polynomial expansion. The jamming coverage size area also determined. By an extrapolation these infinite maximum...

Random sequential adsorption (RSA) of polymer, modeled as a chain identical spheres, is systematically studied. In order to control precisely anisotropy and number degrees freedom, two different kinds polymers are used. the first one, monomers placed along straight line, whereas in second, relative orientations particles random. Such fill flat homogeneous surface randomly. The paper focuses on maximal random coverage ratio kinetics dependence polymer size, shape anisotropy, numbers freedom....

Adsorption of fibrinogen was theoretically studied using the three-dimensional random sequential adsorption (RSA) model. Fibrinogen molecule shape approximated by bead model considering presence flexible side arms. Various cases were considered inter alia, side-on mechanisms and simultaneous side-on/end-on mechanism. The latter is pertinent to at lower pH (below isoelectric point 5.8) where entire positively charged. Extensive calculations enabled one determine jamming surface concentration...

Random sequential adsorption of various two dimensional objects is studied in order to find a shape which maximizes the saturated packing fraction. This investigation was begun our previous paper [Cieśla et al., Phys. Chem. 17, 24376 (2015)], where densest for smoothed dimers. Here this compared with n-mers, spherocylinders, and ellipses. It found that highest fraction out shapes 0.584 05 ± 0.0001 obtained ellipses having long-to-short axis ratio 1.85 0.07.

The adsorption of human serum fibrinogen on polystyrene latex particles was studied using the microelectrophoretic and concentration depletion methods. Measurements were carried out for pH 3.5 an ionic strength range 10–3 to 0.15 M NaCl. electrophoretic mobility determined as a function amount adsorbed (surface concentration). A monotonic increase in (zeta potential) observed, indicating significant all strengths. No changes observed prolonged time periods, suggesting irreversibility...

The influence of different boundary conditions on the density random packings disks is studied. Packings are generated using sequential adsorption algorithm with three types conditions: periodic, open, and wall. It found that finite size effects smallest for periodic conditions, as expected. On other hand, in case open wall boundaries it possible to introduce an effective packing a constant correction term significantly improve densities.

This study examines the diffusion of spherical particles in a conical widening channel, with focus on effects deterministic drift and entropic forces. Through numerical simulations, we analyze motion from reflecting boundary to an absorbing one. Properties diffusive are explored by inspection mean squared displacement first passage time. The results show that type depends strength. Without drift, forces induce effective superdiffusion; however, increasing strength can counterbalance shift...

Random packing of unoriented regular polygons and star on a two-dimensional flat continuous surface is studied numerically using random sequential adsorption algorithm. Obtained results are analyzed to determine the saturated ratio as well its density autocorrelation function. Additionally, kinetics growth available function measured. In general, stars give lower ratios than polygons, but when number vertexes large enough, both shapes approach disks and, therefore, properties their reproduce...

Fibrinogen (Fb) adsorption on positively charged latex particles (average diameter of 800 nm) was studied using the microelectrophoretic and concentration depletion methods based AFM imaging. Monolayers were adsorbed from diluted bulk solutions at pH 7.4 an ionic strength in range 10(-3) to 0.15 M where fibrinogen molecules exhibited average negative charge. The electrophoretic mobility after controlled systematically measured. A monotonic decrease fibrinogen-covered observed for all...

The paper presents an algorithm to generate two-dimensional, saturated random sequential adsorption packings of identical, unoriented, anisotropic convex shapes. method consists in tracking regions where the next shape can be added. was tested on built spherocylinders and ellipses different width-to-height ratio. Obtained packing fractions at saturation agree with earlier predictions using estimation fraction based kinetics growth, but they are much more accurate. Additionally, we discuss...

The random sequential adsorption of various particle shapes is studied in order to determine the influence anisotropy on saturated packing. For all tested particles there an optimal level which maximizes packing fraction. It found that a concave shape derived from dimer disks gives fraction 0.5833, comparable maximum ellipsoids and spherocylinders higher than other shapes. Discussion why this beneficial for given.

Modification of solid substrates by poly-l-lysine (PLL) layers has been widely employed in order to improve their biocompatibility, for promoting protein and cell immobilization fabrication biosensor arrays antibacterial coatings. However, despite many studies conducted the literature, there is a deficiency quantitative description PLL adsorption processes. It postulated that this becomes feasible applying direct experimental techniques combined with thorough theoretical modeling. In work,...

The transport of molecules and particles through single pores is the basis biological processes, including DNA protein sequencing. As individual objects pass a pore, they cause transient change in current that can be correlated with object size, surface charge, even chemical properties. majority experiments modeling have been performed spherical objects, while much less known about characteristics aspherical particles, which would act as model system, for example, proteins bacteria. kinetics...

Irreversible adsorption of spheres on flat collectors having dimension $d<2$ is studied. Molecules are adsorbed Sierpinski's Triangle and Carpet like fractals ($1<d<2$), General Cantor Set ($d<1$). Adsorption process modeled numerically using Random Sequential (RSA) algorithm. The paper concentrates measurement fundamental properties coverages, i.e. maximal random coverage ratio density autocorrelation function, as well RSA kinetics. Obtained results allow to improve phenomenological...

Random packings built of cubes are studied numerically using a random sequential adsorption algorithm. To compare the obtained results with previous reports, three different models cube orientation sampling were used. Also, cube-cube intersection algorithms tested to find most efficient one. The study focuses on mean saturated packing fraction as well kinetics growth. Microstructural properties analyzed density autocorrelation function.

This study presents an algorithm to generate a saturated random packing built of identical, unoriented rectangles. The is based on tracing regions that are unavailable for placing subsequent shapes. If these cover the whole stops because no more objects can be added packing; thus it saturated. used packings rectangles side-to-side length ratio $\ensuremath{\epsilon}\ensuremath{\in}[1.0,2.5]$. densest obtained $\ensuremath{\epsilon}=1.49\ifmmode\pm\else\textpm\fi{}0.02$, and fraction, in this...

Three different algorithms used for eye pupil location were described and tested. Algorithm efficiency comparison was based on human faces images taken from the BioID database. Moreover all localisation methods implemented in a dedicated application supporting movement computer control. In this case face acquired by webcam processed real-time.

Saturated random packing of particles built two identical, relatively shifted spheres in two- and three-dimensional flat homogeneous space was studied numerically using a sequential adsorption algorithm. The shift between centers varied from $0.0$ to $8.0$ sphere diameters. Numerical simulations allowed the determination kinetics, saturated coverage ratio, as well available surface function density autocorrelation function.