Dynamic Self-organization in an Open Reaction Network as a Fundamental Mechanism for the Emergence of Life

<p>The emergence of life on the earth has attracted intense attention but still remained an unsolved question. A key problem is that it has been left unclear why a living organism can have self-organizing ability leading to highly ordered structures and evolutionary behavior. This work reveals by computer simulation and experiments that a stationary state of an open reaction network, into which some source substances flow at constant rates, really has such self-organizing ability. The point is that reaction and diffusion processes in an open reaction network are irreversible and always forced to approach equilibrium. Therefore, they necessarily reach a stationary state in which they approach equilibrium to the largest extent as a whole and attain a full balance. This means that a stationary state of an open reaction network is firmly stabilized by irreversible reaction and diffusion processes and kept stable against fluctuation, namely it has ability to organize itself. A stationary state of an open reaction network is also flexible in structure and can evolve based on its own self-organizing ability through interaction with the environment. Thus, this work provides a new general mechanism of self-organization and evolution in a prebiotic chemical system, which is expected to have acted as a fundamental principle for the emergence of life on the earth. It is interesting to note that a network of reversible processes in a machine has no self-organizing ability because a reversible process has no property of spontaneously and irreversibly happening in a particular direction. </p>

A computational model for diffusion-reaction-deformation coupled problems and its finite element implementation

PurposeA diffusion-reaction-deformation coupled model is employed and implemented as a user-defined element (UEL) subroutine in the commercial finite element software package ABAQUS.Design/methodology/approachChemical reaction and diffusion are treated as two distinct processes by introducing the extent of reaction and the diffusion concentration as two kinds of independent variables, for which the independent governing equations for chemical reaction and diffusion processes are obtained. Furthermore, an exponential form of chemical kinetics, instead of the linearly phenomenological relation, between the reaction rate and the chemical affinity is used to describe reaction process. As a result, complex chemical reaction can be simulated, no matter it is around or away from equilibrium.FindingsTwo numerical examples are presented, one for validation of the model and another for the modeling of the deflection of a plane caused by a chemical reaction.Originality/value1. Independent governing equations for diffusion and reaction processes are given. 2. An exponential relation between the reaction rate and its driving force is employed. 3. The UEL subroutine is used to implement the finite element procedure.

Determination of Inherent Dissolution Performance of Drug Substances

The dissolution behavior of novel active pharmaceutical ingredients (API) is a crucial parameter in drug formulation since it frequently affects the drug release. Generally, a distinction is made between surface-reaction- and diffusion-controlled drug release. Therefore, dissolution studies such as the intrinsic dissolution test defined in the pharmacopeia have been performed for many years. In order to overcome the disadvantages of the common intrinsic dissolution test, a new experimental setup was developed within this study. Specifically, a flow channel was designed and tested for measuring the mass transfer from a flat, solid surface dissolving into a fluid flowing over the surface with well-defined flow conditions. A mathematical model was developed that distinguishes between surface-reaction- and diffusion-limited drug release based on experimental data. Three different drugs—benzocaine, theophylline and griseofulvin—were used to investigate the mass flux during dissolution due to surface reaction, diffusion and convection kinetics. This new technique shows potential to be a valuable tool for the identification of formulation strategies.

INDICATORS OF ERYTHROCYTOPOIESIS IN HERPES INFECTION OF THE FIRST AND SECOND TYPES OF HORSES

The article presents the results of studies of erythrocytopoiesis in horses with herpesvirus infection of the first type (rhinopneumonia) and respiratory manifestations of herpesvirus of the second type and their coexistence in animals. In the general pathology of horses, herpesvirus infections of horses occupy a leading place, and diseases of mixed etiology, which occur with atypical manifestations of clinical signs, are of particular concern. The work was performed in 2018 on the basis of the laboratory of the Department of Microbiology, Pharmacology and Epizootology of Polissya National University on breeding horses belonging to the Nahiryan branch of PJSC "Rise-Maximko" Ternopil region. Blood for the study was taken from the jugular vein against Jugulares in the morning before feeding Diagnostic studies to confirm herpesvirus infection were performed in the reaction of delayed hemagglutination, reaction and diffusion deposition - for herpes of the first type and in the reaction and diffusion precipitation to herpesvirus infection of the second type. Evaluation of erythrocyte indices allows you to get an idea of the characteristics of erythrocytes, which is very important in determining the type of anemia. Erythrocyte indices often respond quickly to the treatment of anemia and can be used to assess the effectiveness of therapy. The studies revealed a significant decrease in the number of leukocytes P ≤ 0.05 in animals of all experimental groups. Regarding hematocrit and erythrocyte counts, a significant decrease in P ≤ 0.05 was found in horses affected by EHV-1, and in the case of coexistence of two types of pathogens - a significant decrease in P ≤ 0.01. Erythrocyte index indices for herpesvirus infection of the first type in horses were characterized by a significant P ≤ 0.05 increase in the mean hemoglobin concentration in erythrocytes and a significant P ≤ 0.05 decrease in the mean erythrocyte volume. In herpesvirus infection of the second type, the fluctuations of the indices were not significant. In the combined course of the two types of viruses in horses, a significant increase in P ≤ 0.05 hemoglobin content in one erythrocyte and a significant P ≤ 0.05 increase in the average volume of erythrocytes.