Study of human erythrocyte membrane proteins by 2-dimensional electrophoresis

Fractionation of human erythrocyte membrane proteins was performed using a modification of two-dimensional gel electrophoresis described by P. O'Farrel with isoelectric point plotted against molecular mass. All major erythrocyte proteins, including high molecular weight proteins, such as spectrin and band 3 protein, identified by one-dimensional sodium dodecyl sulfate gel electrophoresis, were visualized by silver staining of two-dimensional gels. All in all about 50 polypeptides were distinguished on two-dimensional electrophoretic patterns. Preliminary protein map was developed.     

Use of molecular-biological methods for identifying brucella in a comparative analysis of strains, isolated from sick dogs

Ten strains isolated from sick dogs in 1998 in St. Petersburg were studied by traditional and molecular biological methods of Brucella identification. PCR study confirmed that the isolated cultures were Brucellae, and comparative study of the traditional phenotypical characteristics and protein and antigenic composition allowed referring all the isolated strains to B. canis. Traditional identification showed similarity of 7 strains with the reference B. canis strain RM6/66, and 3 strains were similar to B. canis Mex 51 strain. These results confirmed the division of B. canis into two biovars. Polyacrylamide gel electrophoresis with sodium dodecyl sulfate demonstrated the identity of protein profiles of 10 strains isolated from dogs to the reference B. canis RM6/66 strain. Immunoblotting analysis with S- and R-specific rabbit antisera also demonstrated the identity of antigens binding IgG antibodies in the strains isolated from dogs to the reference B. canis RM6/66 strain.     

Loss of hydrogen atoms in H<Subscript>2</Subscript> plasma on the surfaces of materials used in EUV lithography

Low-pressure hydrogen is an important component of the working medium in extreme ultraviolet (EUV) projection lithography. Under the action of EUV photons and fast secondary electrons on the gas medium, plasma and atomic hydrogen, actively interacting with the surface, are produced. This interaction is very important, because it largely determines the lifetime of the multilayered EUV optics. In this study, the loss of atomic hydrogen under the conditions of a low pressure (<10 Torr) RF plasma discharge on the surfaces of materials used in EUV lithography is investigated. The surface loss probabilities of H atoms on these materials are measured. It is shown that surface recombination of atomic hydrogen goes according to the Eley-Rideal mechanism via direct recombination of H atoms from the gas phase with chemically and physically adsorbed atoms. In this case, the surface recombination probability is mainly determined by the density of chemical adsorption sites. The density of adsorption sites and the desorption energy of H atoms are estimated. The desorption energy of physically adsorbed H atoms on pure metal surfaces (or surfaces exposed to plasma) is about 0.5 eV, and the density of sorption sites is close to the surface density of atoms. This results in a high loss probability of H atoms on metals (∼0.1). Therefore, to provide efficient transportation of hydrogen atoms, it is necessary to use materials with the lowest loss probability of H atoms, i.e., dielectrics.     

The Skeletal System as an Additional Storage System for Iodine Isotopes

Biophysics - Using the gamma-spectrometric method we found that the radioactive isotope 125I, when entering the body of a rat, actively accumulated not only in the thyroid gland, but also in the...     

On the rate of evolutionary processes in solitary population waves: Phase transitions in microevolution

It is shown that, like physical systems, populations of species can be in different phases, depending on environmental conditions. These phases, like phases of physical systems, are described by specific state equations. The physical phenomenon of solitary population waves is revealed for the phase of invasion of organisms into their secondary range. The mathematical model has a solution in the form of a solitary wave propagating with a constant speed without changes in shape. The self-organization in solitary waves differs sharply from population processes in the primary species range and is close to the physical foundation of the theory of autosolitons. Solitary waves are impossible within the primary species range. A capacity for the formation of solitary waves is only revealed in phylogenetically young “juvenile taxa.” These coenophobes show the highest rates of adaptive changes, are provoked to expand into new areas. Their phase transitions are distinguished not only by an exclusively wide range of fluctuations of population density, but also high phenotypic variability. The macroevolutionary processes can be provided by juvenile taxa in solitary population waves formed as a result of disruption of ecosystems and invasions. Macrotaxa cannot appear in stable successional systems.     

Natural rock roughness as a key parameter for optimizing seedling adhesion and restoration of the seagrass Posidonia oceanica in its native environment

Seagrasses provide various ecosystem functions in coastal areas of the world. In the Mediterranean Sea, Posidonia oceanica is an endemic species threatened by several activities despite being protected by national and international laws. Currently, several transplanting initiatives have been carried out using different methods, among which those including seeds and seedlings are considered the most ecological and low-cost ones. Beach-cast fruits and seeds can be found in spring and their appearance can easily be reported, through a citizen science approach, by the community. One of the obstacles in using these methods is identifying the best substrate in which to place P. oceanica seeds to facilitate root adhesion of the seedlings prior to their transplantation into the sea. In the present study, we analyzed, using a 3D surface optical microscope, the roughness of natural rocks to identify the availability of specific roughness ranges suitable for adhesion and root anchoring of P. oceanica seedlings. Conventional roughness parameters and roughness power spectral density were calculated for the inner and outer surfaces of 9 different rock samples. Among the rock samples examined, the calcarenitic ones and in particular marsala calcarenite, due to the presence of the “ideal roughness for seedlings” can be considered one of the best consolidated substrates to be used for the construction of ad hoc devices on which plantlet of P. oceanica can grow for the purpose of restoration.     

Methane production by anaerobic digestion of organic waste from vegetable processing facilities

The article concerns converting waste from vegetable processing facilities into methane in anaerobic reactors with a small amount of inoculum (8.4%). Anaerobic digestion of vegetable waste with a high content of organic acids and carbohydrates makes it possible to achieve a methanogenesis productivity of 273–436 L CH₄/kg of volatile solidis, which is comparable to or higher than the productivity of such reactors in the world (according to the literature). The contents of ammonia nitrogen and soluble phosphorus in the form of on undiluted substrate basis in the digested vegetable wastes ranged from 3.39 to 5.06 and from 0.78 to 1.03 g/L respectively. Thus, mineralized vegetable waste can be used as an organic fertilizer with a high nutrient content. The results show the feasibility of the technology of conversion of organic waste from vegetable processing facilities into methane and organic fertilizer in anaerobic fermenters (digesters).