Valeriy V. Lunin

Laser reshaping of costal cartilage for transplantation

Laser reshaping of cartilage is a new effective and safe technique for correction of nasal septum and ear deformities. Costal cartilage is a most suitable natural material for transplantation. The problem is to obtain stable proper shape of cartilage implants. The objective of this article is to study reshaping of porcine costal cartilage for larynx stenosis surgery using Erbium glass fiber laser.

Starch-modified magnetite nanoparticles for impregnation into cartilage

The paper presents preparation and characterization of starch-modified Fe3O4 nanoparticles (NPs) in aqueous dispersion after impregnation into healthy and damaged types of cartilage. We show that starch-modified dispersion has a narrower size distribution than a non‐stabilized one. The average hydrodynamic radius of magnetite NPs in a dispersion used for impregnation into cartilage is (48xa0±xa01) nm with the width of the distribution from 5 to 200xa0nm. We investigate stability of aqueous magnetite NPs dispersions during storage and with increase in temperature (up to 70xa0°C). We find that polydisperse magnetite NPs can penetrate into cartilage and the size and concentration of impregnated particles depend on the organization of the tissue structure. The results confirm the possibility of application of magnetite NPs in diagnostics and laser treatment of degenerative cartilage deceases.

A case of Z/E-isomers elution order inversion caused by cosolvent percentage change in supercritical fluid chromatography.

A case of elution order inversion caused by cosolvent percentage change in supercritical fluid chromatography was observed and investigated in some detail. Z- and E-isomers of phenylisobutylketone oxime experience an elution order reversal on most columns if the mobile phase consists of CO2 and alcohol. At lower percentages of alcohol Z-oxime is retained less, somewhere at 2-5% coelution occurs and at larger cosolvent volume elution order reverses - Z-oxime is eluted later than E-oxime. We suppose inversion with CO2-ROH phases happens due to a shift in balance between two main interactions governing retention. At low ROH percentages stationary phase surface is only slightly covered by ROH molecules so oximes primarily interact with adsorption sites via hydrogen bond formation. Due to intramolecular sterical hindrance Z-oxime is less able to form hydrogen bonds and consequently is eluted first. At higher percentages alcohols occupy most of strong hydrogen bonding sites on silica surface thus leaving non-specific electrostatic interactions predominantly responsible for Z/E selectivity. Z-oxime has a much larger dipole moment than E-oxime and at these conditions it is eluted later. Additional experimental data with CO2-CH3CN, hexane-iPrOH and CHF3-ROH mobile phases supporting this explanation are presented.

Laser radiation effect on chondrocytes and intercellular matrix of costal and articular cartilage impregnated with magnetite nanoparticles.

Magnetic nanoparticles with the ability to absorb laser radiation are the perspective agents for the early diagnostics and laser therapy of degenerative cartilage. The effect of starch stabilized magnetite nanoparticles (SSNPs) on the cartilage structure components has never been studied before. The aim of the work is to establish the Erbium:glass laser effect on costal and articular cartilage impregnated with SSNPs.

Formation of active surface of copper catalysts in methanol oxidation

Features of the process of methanol partial and deep oxidation on supported copper catalysts as compared with silver samples have been studied. The influence of supports of different acid-base nature and modifying additives of Zr, Ce, La and Cs oxides on electronic states of supported copper was investigated by the methods of diffuse reflectance electron spectroscopy, XRD and electron microscopy. By comparison of catalytic and spectroscopic data a conclusion on the nature of active sites of copper catalysts in this process has been made.