Effect of composition and mechanoactivation on the properties of films based on starch and chitosans with high and low deacetylation.

The effect of composition and mechanoactivation in the rotor-stator device on the rheological and film-forming properties of casting blends based on corn starch and chitosans with high (HDC) and low (LDC) deacetylation degree was studied. Films were characterized using optical and atomic force microscopy, X-ray diffraction, FTIR-spectroscopy and by tensile and moisture permeability testing data. An increase in chitosan content was found to result in the blends viscosity increase as well as the tensile strength, elongation and moisture permeability of films. Mechanoactivation was shown to cause an increase in the homogeneity, smoothness and transparency of the films, and an increase in the tensile strength by 1.5 and 2.5 times for the HDC and LDC based films, respectively. It is concluded that the developed eco-friendly and easily implemented method, which allows improving the unsatisfactory properties of starch-chitosan films without the introduction of additional chemicals, can be used on an industrial scale.

Influence of the composition and high shear stresses on the structure and properties of hybrid materials based on starch and synthetic copolymer.

The method of mechanical activation in the rotor-stator device was used to combine the starch hydrogel and the latex of the synthetic copolymer. The compatibility of the components was found to improve consistently by the preliminary mechanoactivation of the starch gel and the joint activation of the mixturs. The joint activation was shown to promote the crystallization of starch and the amorphous phase ordering of the composite. An increase in the starch content and co-activation were found to result in rise in the Young's modulus and tensile strength, but joint activation ensures an increase in the elasticity of the samples. The kinetic parameters of moisture transfer through composite films were estimated. A distinct compensative effect was found, consisted in a significant increase in the sorption coefficient and a decrease in the diffusion coefficient with increasing starch content.

[Comparative pharmacokinetics and relative bioavailability of magnesium-containing drugs].

Pharmacokinetics of magnesium ions after single peroral administration of Magnelis B6 and Magne B6 coated tablets (magnesium dose, 48 mg) was studied in rabbits. In the blood plasma, the level of magnesium ions was very low compared to the endogenous level, which did not allow the drug bioavailability to be reliable evaluated. At the same time, the level of magnesium ions was reliable determined in the daily urine of test animals. The relative bioavailability of magnesium for Magnelis B6 versus Magne B6 was estimated at 98.93 +/- 12.45% (average +/- SD).

[Prospects for designing Russian gene engineering agents for medicine. Rastan is the first Russian recombinant human growth hormone].

The development of modern pharmacology cannot be imagined without the use of genetic engineering methods (recombinant DNA technology). The success of medicine is increasingly based on the active use of protein preparations obtained using the technology of transferring hereditary information (genes) from one organism to another. The emergence of the ability to express foreign genes in the cells of various organisms (both eukaryotes and prokaryotes) has become one of the revolutionary events in the science of the last two decades of the 20th century and laid the foundations of modern biotechnology.